Carbapenem antibiotics

ABSTRACT

Disclosed are novel carbapenem derivatives characterized by a 2-substituent of the formula ##STR1## in which A represents cyclopentylene, cyclohexylene or C 2  -C 6  alkylene optionally substituted by one or more C 1  -C 4  alkyl groups; R 5  represents either (a) an optionally substituted aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aryl, araliphatic, heteroaryl, heteroaraliphatic, heterocyclyl or heterocyclyl-aliphatic radical or (b) a divalent phenylene or C 1  -C 4  alkylene group joined to the ##STR2## ring so as to form a bridged polycyclic group; and ##STR3## represents a quaternized nitrogen-containing non-aromatic heterocycle. Such derivatives are useful as potent antibacterial agents.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of our co-pending applicationSer. No. 389,652 filed June 18, 1982, abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to new carbapenem antibiotics in whichthe 2-substituent has the formula ##STR4## in which A represents astraight or branched chain alkylene group or a cyclopentylene orcyclohexylene group; R⁵ represents either (a) an optionally substitutedaliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aryl, araliphatic,heteroaryl, heteroaraliphatic, heterocyclyl or heterocyclyl-aliphaticradical or (b) a divalent phenylene or C₁ -C₄ alkylene group joined tothe ##STR5## ring so as to form a bridged polycyclic group; and ##STR6##represents a quaternized nitrogen-containing non-aromatic heterocycle.

2. Description of the Prior Art

A number of β-lactam derivatives containing the carbapenem nucleus##STR7## have been disclosed in the literature. These carbapenemderivatives have been reported to possess utility as antibacterialagents and/or β-lactamase inhibitors.

The initial carbapenem compounds were natural products such asthienamycin of the formula ##STR8## obtained by fermentation ofStreptomyces cattleya (U.S. Pat. No. 3,950,357). Thienamycin is anexceptionally potent broadspectrum antibiotic which possesses notableactivity against various Pseudomonas species, organisms which have beennotoriously resistant to β-lactam antibiotics.

Other natural products containing the carbapenem nucleus includeolivanic acid derivatives such as antibiotic MM 13902 of the formula##STR9## disclosed in U.S. Pat. No. 4,113,856, antibiotic MM 17880 ofthe formula ##STR10## disclosed in U.S. Pat. No. 4,162,304, antibioticMM 4550A of the formula ##STR11## disclosed in U.S. Pat. No. 4,172,129and antibiotic 890A₉ of the formula ##STR12## disclosed in U.S. Pat. No.4,264,735. In addition to the natural products, the compound desacetyl890A₁₀ of the formula ##STR13## is disclosed in U.S. Pat. No. 4,264,734as being prepared by an enzymatic deacylation of the correspondingN-acetyl compound. Various derivatives of the naturally-occuringolivanic acids have also been synthesized, e.g. the compounds of theformula ##STR14## wherein CO₂ R₁ is a free, salted or esterifiedcarboxyl group, n is 0 or 1 and R₂ is H, an acyl group or a group of theformula R₃ O₃ S wherein R₃ is a salting ion or a methyl or ethyl group,disclosed in European Patent Application No. 8885.

U.S. Pat. No. 4,235,922 (see also European Patent Application 2058)discloses the carbapenem derivative of the formula ##STR15## while U.K.Patent Application No. 1,598,062 reports isolation of the compound##STR16## from a Streptomyces fermentation broth.

Carbapenems which are unsubstituted in the 6-position have also beensynthesized. Thus, U.S. Pat. No. 4,210,661 discloses compounds of theformula ##STR17## wherein R₂ is phenyl or substituted phenyl, U.S. Pat.No. 4,267,177 discloses compounds of the formula ##STR18## wherein R₁ isan optionally substituted pyridyl group, U.S. Pat. No. 4,255,441discloses compounds of the formula ##STR19## wherein R₂ and R₃ are H oralkyl and R₄ is NH-CO_(n) R₆ in which R₆ is alkyl, phenyl or substitutedphenyl and n is 1 or 2, and U.S. Pat. No. 4,282,236 discloses compoundsof the formula ##STR20## wherein R₁ is H or alkyl and R₂ is CN or CO₂ R₃in which R₃ is H, alkyl, aryl or aralkyl.

Carbapenems of the general formula ##STR21## wherein R¹ is H or acyl andR⁸ is H or substituted or unsubstituted: alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, aryl, aralkyl, aralkenyl,aralkynyl, heteroaryl, heteroaralkyl, heterocyclyl or heterocyclylalkyl,are disclosed in U.S. Pat. No. 4,218,463. There is no disclosure of anyheterocyclylalkyl R⁸ substituents of the type ##STR22## in which A isalkylene and ##STR23## is a quaternized nitrogen-containing non-aromaticheterocycle.

The natural product thienamycin has the absolute configuration 5R, 6S,8R. This isomer, as well as the remaining seven thienamycin isomers, maybe obtained via total synthesis as disclosed in U.S. Pat. No. 4,234,596.Total synthesis procedures for thienamycin are also disclosed, forexample, in U.S. Pat. Nos. 4,287,123, 4,269,772, 4,282,148, 4,273,709,4,290,947 and European Patent Application No. 7973. A key intermediatein the disclosed synthetic methods is ##STR24## wherein pNB representsp-nitrobenzyl.

Because of the exceptional biological activity of thienamycin, a largenumber of derivatives have been prepared and disclosed in theliterature. Among these are (1) N-formimidoyl thienamycin of the formula##STR25## disclosed in European Patent Application 6639; (2)N-heterocyclic derivatives of thienamycin having the formula ##STR26##wherein: the bifunctional ring may contain additional unsaturation inthe ring; and wherein n is an integer selected from 1-6; p is 0, 1 or 2;R¹ is H, alkyl or aryl; and Z is imino, oxo, H, amino or alkyl,disclosed in U.S. Pat. No. 4,189,493; (3) substituted N-methylenederivatives of thienamycin having the formula ##STR27## wherein X and Yare H, R, OR, SR or NR¹ R² in which R is substituted or unsubstituted:alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl,heteroaryl, heteroaralkyl, heterocyclyl or heterocyclylalkyl, and R¹ andR² are H or R, disclosed in U.S. Pat. No. 4,194,047; (4) compounds ofthe formula ##STR28## wherein R³ is aryl, alkyl, acyl or aralkyl and R¹and R² are independently selected from H and acyl (including acyl of thetype ##STR29## in which R¹¹ may inter alia be alkyl substituted by aquaternary ammonium group, e.g. ##STR30## disclosed in U.S. Pat. No.4,226,870; (5) compounds of the formula ##STR31## wherein R³ is H, acylor an univalent optionally substituted hydrocarbon radical; R¹ isoptionally substituted alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkenylalkyl, cycloalkylalkyl, aryl, aralkyl,heteroaryl or heteroaralkyl and R² is acyl (including acyl of the type##STR32## in which R is alkyl substituted by a quaternary ammoniumgroup, e.g. ##STR33## disclosed in U.K. Pat. No. 1,604,276 (see alsoU.S. Pat. No. 4,235,917); (6) compounds of the formula ##STR34## whereinR⁵, R⁶ and R⁷ are independently selected from H and substituted orunsubstituted: alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl,cycloalkenylalkyl, cycloalkylalkyl, aryl, aralkyl, heteroaryl orheteroaralkyl, are disclosed in U.S. Pat. No. 4,235,920; (7) compoundsof the formula ##STR35## wherein each of R¹ and R², independently of theother, is a radical of the type defined for R, a hydrogen atom, or anitro, hydroxyl, C₁₋₆ alkoxyl, amino, C₁₋₆ alkylamino, di(C₁₋₆alkyl)amino or tri(C₁₋₆ alkylamino) radical, an extra anion beingpresent in the latter case; or R¹ and R² are joined together to form,together with the nitrogen atom to which they are attached, asubstituted or unsubstituted monocyclic or bicyclic heteroaryl orheterocyclyl residue containing 4-10 ring atoms, one or more of whichmay be an additional hetero atom selected from oxygen, sulphur andnitrogen; R is a cyano group or a substituted or unsubstitutedcarbamoyl, carboxyl, (C₁₋₁₀ alkoxy)carbonyl, C₁₋₁₀ alkyl, C₂₋₁₀ alkenyl,C₂₋₁₀ alkynyl, C₃₋₁₀ cycloalkyl, C₄₋₁₂ cycloalkylalkyl, C₅₋₁₂cycloalkylalkenyl, C₃₋₁₀ cycloalkenyl, C₅₋₁₂ cycloalkenylalkenyl, C₄₋₁₂cycloalkenylalkyl, C₆₋₁₀ aryl, C₇₋₁₆ aralkyl, C₈₋₁₆ aralkenyl, C₈₋₁₆aralkynyl or monocyclic or bicyclic heteroaryl, heteroaralkyl,heterocyclyl or heterocyclylalkyl comprising 4 to 10 ring atoms one ormore of which is a hetero atom selected from oxygen, sulphur andnitrogen and in which the alkyl residue of the heteroaralkyl orheterocyclylalkyl radical contains from 1 to 6 carbon atoms; thesubstituent or substituents on R, R¹, R² or on the ring formed byjoining R¹ and R² are chlorine; bromine; iodine; fluorine; azido; C₁₋₄alkyl; mercapto; sulpho; phosphono; cyanothio (-SCN); nitro; cyano;amino; hydrazino; amino or hydrazino having up to three C₁₋₆ alkylsubstituents; hydroxy; C₁₋₆ alkoxy; C₁₋₆ alkylthio; carboxyl; oxo; (C₁₋₆alkoxy)carbonyl; C₂₋₁₀ acyloxy; carbamoyl; (C₁₋₄ alkyl) carbamoyl ordi(C₁₋₄ alkyl) carbamoyl; R₃ is a hydrogen atom, an acyl radical or aradical of the type defined for R⁴ ; R⁴ is C₁₋₁₀ alkyl; substitutedcarbonylmethyl; (C₁₋₆ alkoxy)-(C₁₋₆ alkyl), (C₃₋₆ cycloalkoxy)(C₁₋₆alkyl); C₂₋₁₂ alkanoyloxyalkyl; partially or completely halogenated C₁₋₆alkyl in which the halogen(s) is/are chlorine, bromine or fluorine;aminoalkyl; C₂₋₁₀ alkenyl; C₂₋₁₀ alkynyl; acyl; C₃₋₁₄alkoxycarbonylalkyl; C₄₋₂₁ dialkylaminoacetoxyalkyl; C₂₋₁₃alkanoylaminoalkyl; ar-(C₁₋₃ alkyl) in which the aryl residue containsfrom 6 to 10 carbon atoms; monocyclic or bicyclic heteroaralkyl orheterocyclylalkyl containing 4 to 10 ring atoms, 1 to 3 carbon atoms inthe alkyl residue, and 1-4 hetero atoms selected from oxygen, sulphurand/or nitrogen; nuclear-substituted aralkyl or heteroaralkyl in whichthe substituent is chlorine, fluorine, bromine, iodine or C₁₋₆ alkyl;aryl or nuclearsubstituted aryl containing 6 to 10 ring carbon atoms andin which any nuclear substituent is hydroxy, C₁₋₆ alkyl, chlorine,fluorine or bromine; aralkoxyalkyl; C₂₋₁₂ alkylthioalkyl; C₄₋₁₂cycloalkylthioalkyl; (C₂₋₁₀ acylthio)-(C₁₋₆ alkyl); or phenylalkenyl inwhich alkenyl has 2-6 carbon atoms; R.sup. 5 is substituted orunsubstituted C₁₋₁₀ alkyl; C₂₋₁₀ alkenyl or alkynyl; ring substitutedand unsubstituted cycloalkyl, cycloalkenyl, cycloalkenylalkyl, andcycloalkylalkyl having 3-6 ring carbon atoms and up to 6 carbon atoms inany chain; C₆₋₁₀ aryl; aralkyl having 6-10 ring carbon atoms and 1-6carbon atoms in the alkyl chain; monocyclic or bicyclic heteroaryl orheteroaralkyl containing 4-10 ring atoms, one or more of which isoxygen, nitrogen or sulphur, and 1-6 carbon atoms in the alkyl chain;and the ring or chain substituent(s) is/are chlorine, bromine, iodine,fluorine, azido, cyano, amino, C₁₋₆ alkylamino, di(C₁₋₆ alkyl)amino ortri(C₁₋₆ alkylamino) radical, an extra anion being present in the lattercase, hydroxy, C₁₋₆ alkoxy, C₁₋₆ alkylthioalkyl; carboxyl; oxo, (C₁₋₆alkoxy)carbonyl; C₂₋₁₀ acyloxy; carbamoyl; (C₁₋₄ alkyl)-carbamoyl;di(C₁₋₄ alkyl)carbamoyl; cyanothio (--SCN) or nitro; R⁶ is hydrogen,hydroxy, mercapto, R, --OR, --SR or NR¹ R², where R, R¹ and R² are asdefined above;

X is hydroxy, mercapto, amino, acyloxy --OR⁴, --SR⁴, --NHR⁴, ##STR36##--OM, OQ or, when the compound is in zwitterionic form, --O⁻, in whichcase A⁻ is absent;

A, when the compound is not in zwitterionic form, is a counter ion;

M is a pharmaceutically acceptable cation; and

Q is a blocking group as herein defined, are disclosed in U.K. PatentNo. 1,604,275; and (8) compounds of the formula ##STR37## attached tothe amino nitrogen group of thienamycin represents a mono- or polycyclicN-containing heterocyclic group and R is H, substituted orunsubstituted: alkyl, aryl, alkenyl, heterocyclylalkenyl, aralkenyl,heterocyclylalkyl, aralkyl, --NR₂, COOR, CONR₂, --OR, or CN, aredisclosed in European Patent Application No. 21082. Among the compoundsdisclosed in U.S. Pat. 4,235,920 is ##STR38## wherein A is apharmaceutically acceptable anion. The abovementioned quaternary aminederivative is also described in Recent Advances in the Chemistry ofβ-Lactam Antibiotics, Royal Society of Chemistry, London, 1981, pg240-254, where its antibacterial activity on average is reported asapproximately 1/2 to 2/3 that of thienamycin.

Carbapenem derivatives having a wide variety of 6-substituents inaddition to those mentioned above have also been synthesized. Thus, forexample, (1) European Patent Application No. 40408 discloses compoundsof the formula ##STR39## wherein R₁ is H, methyl or hydroxyl and R₅₁ isa monovalent organic group including inter alia heterocyclicmethyl; (2)European Patent Application 8514 discloses compounds of the formula##STR40## wherein R₁ is an optionally substituted pyrimidinyl group andR₂ is hydrogen or a group CR₃ R₄ R₅ wherein R₃ is hydrogen or hydroxy,R₄ is hydrogen or alkyl and R₅ is hydrogen, alkyl, benzyl or phenyl, orR₅ and R₄ together form a carbocyclic ring; (3) European PatentApplication 38869 discloses compounds of the formula ##STR41## whereinR⁶, R⁷, and R⁸ are independently selected from the group consisting ofhydrogen, substituted and unsubstituted: alkyl, alkenyl, and alkynyl,having from 1-10 carbon atoms; cycloalkyl, cycloalkylalkyl, andalkylcycloalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6carbon atoms in the alkyl moieties; aryl, such as phenyl; aralkyl,aralkenyl, and aralkynyl wherein the aryl moiety is phenyl and thealiphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl,heterocyclyl and heterocyclylalkyl; wherein the substituent orsubstituents relative to the above-named radicals are selected from thegroup consisting of: ##STR42## wherein, relative to the above listedsubstituents on R⁶, R⁷, and R⁸, the groups R¹ and R² are independentlyselected from: hydrogen, alkyl, alkenyl, and alkynyl, having from 1-10carbon atoms; cycloalkyl, cycloalkylalkyl, and alkylcycloalkyl, having3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms in thealkyl moieties; aryl, such as phenyl; aralkyl, aralkenyl, and aralkynylwherein the aryl moiety is phenyl and the aliphatic portion has 1-6carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl andheterocyclylalkyl and wherein the hetero atom or atoms in theabove-named heterocyclic moieties are selected from the group consistingof 1-4 oyxgen, nitrogen or sulphur atoms and wherein the alkyl moietiesassociated with said heterocyclic moieties have 1-6 carbon atoms. (Seealso European Patent Applications Nos. 1627, 1628, 10317, 17992, 37080,37081, and 37082); (4) European Patent Application No. 24832 disclosescompounds of the formula ##STR43## wherein R¹ is H or a group selectedfrom OH, OSO₃ H or a salt or C₁₋₄ alkyl ester thereof, OR², SR³, OCOR²,OCO₂ R³ or OCONHR³, where R² is a C₁₋₆ alkyl group or an optionallysubstituted benzyl group and R³ is a C₁₋₆ alkyl group or an optionallysubstituted benzyl or phenyl group and R¹² is C₁₋₆ alkyl, C₂₋₆ alkenyl,C₃₋₆ alkynyl wherein the triple bond is not present on the carbonadjacent to the sulfur atom, aralkyl, C₁₋₆ alkanoyl, aralkanoyl,aryloxyalkanoyl or arylcarbonyl, any of such R¹² groups being optionallysubstituted, as antibacterial agents.

European Patent Application No. 44170 discloses carbapenem derivativesof the formula ##STR44## wherein R³ is hydrogen or an organic groupbonded via a carbon atom to the carbapenem ring, n is 0 or 1, X is asaturated or unsaturated hydrocarbon radical optionally substituted bybromo or chloro, and R⁴ is a C₁₋₆ alkyl, C₂ -C₆ alkenyl, C₁ -C₁₀ aralkylor aryl group, any of such groups R⁴ being optionally substituted. Thereis no disclosure, however, of any compounds wherein the tetrazole ringis bonded to X via a quaternized nitrogen atom, i.e. a positivelycharged nitrogen which is not attached to a hydrogen atom.

European Patent Application No. 38,869 mentioned above disclosessynthesis of the carbapenem derivatives via intermediates of the generalformula ##STR45## wherein R⁶ and R⁷ are as defined above and R₂ ' is areadily removable carboxyl protecting group. Also disclosed asintermediates are compounds of the formula ##STR46##

wherein X is described as a leaving group.

While, as indicated above, the prior art has described carbapenemderivatives having a 2-substituent of the general formula

    --S--A--Het

wherein A represents an alkylene group and Het represents a heterocyclicor heteroaromatic group, there has been no disclosure of whichapplicants are aware teaching carbapenems wherein Het is a radical ofthe formula ##STR47## in which R⁵ is either (a) an optionallysubstituted aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aryl,araliphatic, heteroaryl, heteroaraliphatic, heterocyclyl orheterocyclylaliphatic radical or (b) a divalent phenylene or C₁ -C₄alkylene group joined to the ##STR48## ring so as to form a bridgedpolycyclic group, and represents a quaternized nitrogen-containingnon-aromatic heterocycle bonded to the alkylene carbon via thequaternary nitrogen atom. As mentioned above, the carbapenem having##STR49## as the 2-substituent has also been reported.

Despite the vast number of carbapenem derivatives disclosed in theliterature, there is still a need for new carbapenems since knownderivatives may be improved upon in terms of spectrum of activity,potency, stability and/or toxic side effects.

SUMMARY OF THE INVENTION

The present invention provides a novel series of carbapenem derivativescharacterized by a 2-substituent of the formula ##STR50## in which Arepresents a straight of branched chain alkylene group or acyclopentylene or cyclohexylene group; R⁵ represents either (a) anoptionally substituted aliphatic, cycloaliphatic,cycloaliphatic-aliphatic, aryl, araliphatic, heteroaryl,heteroaraliphatic, heterocyclyl or heterocyclyl-aliphatic radical or (b)a divalent phenylene or C₁ -C₄ alkylene group joined to the ##STR51##ring so as to form a bridged polycyclic group; and represents aquaternized nitrogen-containing non-aromatic heterocycle. Morespecifically, the present invention provides carbapenem derivatives ofthe formula ##STR52## wherein R⁸ is hydrogen and R¹ is selected from thegroup consisting of hydrogen; substituted and unsubstituted: akyl,alkenyl and alkynyl, having from 1-10 carbon atoms; cycloalkyl andcycloalkylalkyl, having 3-6 carbon atoms in the cycloalkyl ring and 1-6carbon atoms in the alkyl moieties; phenyl; aralkyl, aralkenyl andaralkynyl wherein the aryl moiety is phenyl and the aliphatic portionhas 1-6 carbon atoms; heteroaryl, heteroaralkyl, heterocyclyl andheterocyclylalkyl wherein the hetero atom or atoms in the above-namedheterocyclic moieties are selected from the group consisting of 1-4oxygen, nitrogen or sulfur atoms and the alkyl moieties associated withsaid heterocyclic moieties have 1-6 carbon atoms; wherein thesubstituent or substituents relative to the above-named radicals areindependently selected from the group consisting of ##STR53## wherein,relative to the above-named substituents, the groups R³ and R⁴ areindependently selected from hydrogen; alkyl, alkenyl and alkynyl, havingfrom 1-10 carbon atoms; cycloalkyl, cycloalkylalkyl and alkylcycloalkyl,having 3-6 carbon atoms in the cycloalkyl ring and 1-6 carbon atoms inthe alkyl moieties; phenyl; aralkyl, aralkenyl and aralkynyl wherein thearyl moiety is phenyl and the aliphatic portion has 1-6 carbon atoms;and heteroaryl, heteroaralkyl, heterocyclyl and heterocyclylalkylwherein the hetero atom or atoms in the above-named heterocyclicmoieties are selected from the group consisting of 1-4 oxygen, nitrogenor sulfur atoms and the alkyl moieties associated with said heterocyclicmoieties have 1-6 carbon atoms, or R³ and R⁴ taken together with thenitrogen to which at least one is attached may form a 5-or 6-memberednitrogen-containing heterocyclic ring; R⁹ is as defined for R³ exceptthat it may not be hydrogen; or wherein R¹ and R⁸ taken togetherrepresent C₂ -C₁₀ alkylidene or C.sub. 2 -C₁₀ alkylidene substituted byhydroxy; R⁵ is selected from the group consisting of substituted andunsubstituted: alkyl, alkenyl and alkynyl, having from 1-10 carbonatoms; cycloalkyl and cycloalkylalkyl, having 3-6 carbon atoms in thecycloalkyl ring and 1-6 carbon atoms in the alkyl moieties; phenyl;aralkyl, aralkenyl and aralkynyl wherein the aryl moiety is phenyl andthe aliphatic portion has 1-6 carbon atoms; heteroaryl, heteroaralkyl,heterocyclyl and heterocyclylalkyl wherein the hetero atom or atoms inthe above-named heterocyclic moieties are selected from the groupconsisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkylmoieties associated with said heterocyclic moieties have 1-6 carbonatoms; wherein the above-named R⁵ radicals are optionally substituted by1-3 substituents independently selected from:

    ______________________________________                                        C.sub.1C.sub.6 alkyl optionally substituted by amino,                         fluoro, chloro, carboxyl, hydroxy or carbamoyl;                               fluoro, chloro or bromo;                                                      OR.sup.3 ;                                                                    OCO.sub.2 R.sup.3 ;                                                           OCOR.sup.3 ;                                                                  OCONR.sup.3 R.sup.4 ;                                                         OSO.sub.2 R.sup.3 ;                                                           oxo;                                                                          NR.sup.3 R.sup.4 ;                                                            R.sup.3 CONR.sup.4;                                                           NR.sup.3 CO.sub.2 R.sup.4 ;                                                   NR.sup.3 CONR.sup.3 R.sup.4 ;                                                 NR.sup.3 SO.sub.2 R.sup.4 ;                                                   SR.sup.3 ;                                                                     ##STR54##                                                                     ##STR55##                                                                    SO.sub.3 R.sup.3 ;                                                            CO.sub.2 R.sup.3 ;                                                            CONR.sup.3 R.sup.4 ;                                                          CN; or                                                                        phenyl optionally substituted by 1-3 fluoro,                                  chloro, bromo, C.sub.1C.sub.6 alkyl, OR.sup.3, NR.sup.3 R.sup.4,              SO.sub.3 R.sup.3, CO.sub.2 R.sup.3 or CONR.sup.3 R.sup.4 , wherein            R.sup.3, R.sup.4 and                                                          R.sup.9 in such R.sup.5 substituents are as defined above;                    ______________________________________                                    

or R⁵ may represent a divalent phenylene or C₁ -C₄ alkylene group joinedto the ##STR56## ring so as to form a bridged polycyclic group; A iscyclopentylene, cyclohexylene or C₂ -C₆ alkylene optionally substitutedby one or more C₁ -C₄ alkyl groups; R² is hydrogen, an anionic charge ora conventional readily removable carboxyl protecting group, providingthat when R² is hydrogen or a protecting group, there is also present acounter ion; and ##STR57## represents a substituted or unsubstitutedmono-, bi- or polycyclic non-aromatic heterocyclic radical containing atleast one nitrogen in the ring and attached to A through a ringnitrogen, thereby forming a quaternary ammonium group; or apharmaceutically acceptable salt thereof.

The compounds of formula I are potent antibacterial agents orintermediates useful in the preparation of such agents.

Also included in the invention are processes for preparing the novelcarbapenem derivatives described above and pharmaceutical compositionscontaining the biologically active carbapenem derivatives in combinationwith pharmaceutically acceptable carriers or diluents.

DETAILED DESCRIPTION

The novel compounds of general formula I above contain the carbapenemnucleus ##STR58## and may thus be named as 1-carba-2-penem-3-carboxylicacid derivatives. Alternatively, the compounds may be considered to havethe basic structure and named as 7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylic acid derivatives. While the presentinvention includes compounds wherein the relative stereochemistry of the5,6-protons is cis as well as trans, the preferred compounds have the5R,6S (trans) stereochemistry as in the case of thienamycin.

The compounds of formula I may be unsubstituted in the 6-position orsubstituted by substituent groups previously disclosed for othercarbapenem derivatives. More specifically, R⁸ may be hydrogen and R¹ maybe hydrogen or a non-hydrogen substituent disclosed, for example, inEuropean Patent Application 38,869 (see definition of R₆).Alternatively, R⁸ and R¹ taken together may be C₂ -C₁₀ alkylidene or C₂-C₁₀ alkylidene substituted, for example, by hydroxy.

To elaborate on the definitions for R¹ and R⁸ :

(a) The aliphatic "alkyl", "alkenyl" and "alkynyl" groups may bestraight or branched chain having 1-10 carbon atoms; preferred are 1-6,most preferably 1-4, carbon groups; when part of another substituent,e.g. as in cycloalkylalkyl, or heteroaralkyl or aralkenyl, the alkyl,alkenyl and alkynyl group preferably contains 1-6, most preferably 1-4,carbon atoms.

(b) "heteroaryl" includes mono-, bi- and polycyclic aromaticheterocyclic groups containing 1-4 O, N or S atoms; preferred are 5- or6-membered heterocyclic rings such as thienyl, furyl, thiadiazolyl,oxadiazolyl, triazolyl, isothiazolyl, thiazolyl, imidazolyl, isoxazolyl,tetrazolyl, oxazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl,pyrrolyl, pyrazolyl, etc.

(c) "heterocyclyl" includes mono-, bi- and polycyclic saturated orunsaturated non-aromatic heterocyclic groups containing 1-4 O, N or Satoms; preferred are 5- or 6-membered heterocyclic rings such asmorpholinyl, piperazinyl, piperidyl, pyrazolinyl, pyrazolidinyl,imidazolinyl, imidazolidinyl, pyrrolinyl, pyrrolidinyl, etc.

(d) "halo" includes chloro, bromo, fluoro and iodo and is preferablychloro, fluoro or bromo.

The term "conventional readily removable carboxyl protecting group"refers to a known ester group which has been employed to block acarboxyl group during the chemical reaction steps described below andwhich can be removed, if desired, by methods which do not result in anyappreciable destruction of the remaining portion of the molecule, e.g.by chemical or enzymatic hydrolysis, treatment with chemical reducingagents under mild conditions, irradiation with ultraviolet light orcatalytic hydrogenation. Examples of such ester protecting groupsinclude benzhydryl, allyl, p-nitrobenzyl, 2-naphthylmethyl, benzyl,trichloroethyl, silyl such as trimethylsilyl, phenacyl, p-methoxybenzyl,acetonyl, o-nitrobenzyl, 4-pyridylmethyl and C₁ -C₆ alkyl such asmethyl, ethyl or t-butyl. Included within such protecting groups arethose which are hydrolyzed under physiological conditions such aspivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl and methoxymethyl.Particularly advantageous carboxyl protecting groups are p-nitrobenzylwhich may be readily removed by catalytic hydrogenolysis and allyl whichcan be removed by Pd(Pφ₃)₄ -catalyzed reaction.

The pharmaceutically acceptable salts referred to above include thenontoxic acid addition salts, e.g. salts with mineral acids such ashydrochloric, hydrobromic, hydroiodic, phosphoric, sulfuric, etc. andsalts with organic acids such as maleic, acetic, citric, succinic,benzoic, tartaric, fumaric, mandelic, ascorbic, lactic, gluconic andmalic. Compounds of formula I in the form of acid addition salts may bewritten as ##STR59## R² =H or protecting group

where X.sup.⊖ represents the acid anion. The counter anion X.sup.⊖ maybe selected so as to provide pharmaceutically acceptable salts fortherapeutic administration but, in the case of intermediate compounds offormula I, X.sup.⊖ may be a toxic anion. In such a case the ion can besubsequently removed or substituted by a pharmaceutically acceptableanion to form an active end product for therapeutic use. When acidic orbasic groups are present in the R¹ or R⁵ group or on the ##STR60##radical, the present invention may also include suitable base or acidsalts of these functional groups, e.g. acid addition salts in the caseof a basic group and metal salts (e.g. sodium, potassium, calcium andaluminum), the ammonium salt and salts with nontoxic amines (e.g.trialkylamines, procaine, dibenzylamine, 1-ephenamine,N-benzyl-β-phenethylamine, N,N'-dibenzylethylenediamine, etc.) in thecase of an acidic group.

Compounds of formula I wherein R² is hydrogen, an anionic charge or aphysiologically hydrolyzable ester group together with pharmaceuticallyacceptable salts thereof are useful as antibacterial agents. Theremaining compounds of formula I are valuable intermediates which can beconverted into the abovementioned biologically active compounds.

A preferred embodiment of the present invention comprises compounds offormula I wherein R⁸ is hydrogen and R¹ is hydrogen, CH₃ CH₂ - ##STR61##Among this subclass, the preferred compounds are those in which R¹ is##STR62## most preferably compounds having the absolute configuration5R, 6S, 8R.

Another preferred embodiment comprises compounds of formula I in whichR¹ and R⁸ taken together form an alkylidene radical of the formula##STR63##

The alkylene or cycloalkylene substituent A in the compounds of formulaI may be C₂ -C₆ alkylene (straight chain) optionally substituted by oneor more (preferably 1 or 2) C₁ -C₄ alkyl groups or it may becyclopentylene or cyclohexylene. The alkylene A substituent ispreferably straight or branched chain alkylene of from 2 to 6 carbonatoms. A cycloalkylene A substituent is preferably cyclopentylene of theformula ##STR64## or cyclohexylene of the formfula ##STR65## A preferredembodiment comprises those compounds in which A is ##STR66## or-(CH₂)_(n) - in which n is 2, 3 or 4 and a particularly preferredembodiment comprises those compounds where A is --CH₂ CH₂ --, --CH₂ CH₂CH₂ --, ##STR67##

The alkylene or cycloalkylene moiety "A" is attached to an N-substitutedquaternized non-aromatic heterocycle of the general formula ##STR68##

wherein the R⁵ substituent may be either (a) an optionally substitutedC₁ -C₆ alkyl, C₂ -C₁₀ alkenyl, C₂ -C₁₀ alkynyl, C₃ -C₆ cycloalkyl, C₃-C₆ cycloalkyl-C₁ -C₆ alkyl, phenyl, phenyl-C₁ -C₆ alkyl, phenyl-C₂ -C₆alkenyl, phenyl-C₂ -C₆ alkynyl, heteroaryl, heteroaralkyl in which thealkyl moiety has 1-6 carbon atoms, heterocyclyl o heterocyclylalkyl inwhich the alkyl moiety has 1-6 carbon atoms or (b) a divalent phenyleneor C₁ -C₄ alkylene group joined to the ##STR69## ring so as to form abridged ring polycyclic group, e.g. a quinuclidine group. The heteroaryl(or heteroaryl portion of heteroaralkyl) substituent may be a mono-, bi-or polycyclic aromatic heterocyclic group containing 1-4 O, N or Satoms; preferred are 5- or 6-membered heterocyclic rings such asthienyl, furyl, thiadiazolyl, oxadiazolyl, triazolyl, isothiazolyl,thiazolyl, imidazolyl, isoxazolyl, tetrazolyl, oxazolyl, pyridyl,pyrazinyl, pyrimidinyl, pyridazinyl, pyrrolyl and pyrazolyl. Theheterocyclyl (or heterocyclyl portion of heterocyclylalkyl) substituentmay be a mono-, bi- or polycyclic saturated or unsaturated non-aromaticheterocyclic group containing 1-4 O, N or S atoms; preferred are 5- or6-mentioned heterocyclic rings such as morpholinyl, piperazinyl,piperidyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinylpyrrolinyl and pyrrolidinyl.

In the case where the R⁵ substituent is an alkyl, alkenyl, alkynyl,cycloalkyl, cycloalkylalkyl, phenyl, phenylalkyl, phenylalkenyl,phenylalkynyl, heteroaryl, heteroaralkyl, heterocyclyl orheterocyclylalkyl group, such groups may be optionally substituted by1-3 substituents independently selcted from:

(a) C₁ -C₆ alkyl optionally substituted by, preferably 1-3, amino,fluoro, chloro, carboxyl, hydroxy or carbamoyl groups;

(b) fluoro, chloro or bromo;

(c) --OR³ ;

(d) --OCO₂ R³ ;

(c) --OCOR³ ;

(f) --OCONR³ R⁴ ;

(g) --OSO₂ R³ ;

(h) --oxo;

(i) --NR³ R⁴ ;

(j) R³ CONR⁴ --;

(k) --NR³ CO₂ R⁴ ;

(l) --NR³ CONR³ R⁴ ;

(m) --NR³ SO₂ R⁴ ;

(n) --SR³ ;

(o) --SOR⁹ ;

(p) --SO₂ R⁹ ;

(q) --SO₃ R³ ;

(r) --CO₂ R³ ;

(s) --CONR³ R⁴ ;

(t) --CN; or

(u) phenyl optionally substituted by 1-3 substituents independentlyselected from fluoro, chloro, bromo, C₁ -C₆ alkyl, --OR³, --NR³ R⁴,--SO₃ R³, --CO₂ R³ or --CONR³ R⁴, wherein, relative to the above-namedR⁵ substituents, the groups R³ and R⁴ are independently selected fromhydrogen; alkyl, alkenyl and alkynyl, having 1-10 carbon atoms;cycloalkyl, cycloalkylalkyl and alkylcycloalkyl, having 3-6 carbon atomsin the cycloalkyl ring and 1-6 carbon atoms in the alkyl moieties;phenyl; aralkyl, aralkenyl and aralkynyl wherein the aryl moiety isphenyl and the aliphatic portion has 1-6 carbon atoms; and heteroaryl,heteroaralkyl, heterocyclyl and heterocyclylalkyl wherein the heteroaryland heterocyclyl group or portion of a group is as defined above for R⁵and the alkyl moieties associated with said heterocyclic moieties have1-6 carbon atoms; or R³ and R⁴ taken together with the nitrogen to whichat least one is attached may form a 5- or 6-membered nitrogen-containingheterocyclic (as defined above for R⁵) ring; and R⁹ is as defined abovefor R³ except that it may not be hydrogen. A most preferred R⁵substituent is C₁ -C₆ alkyl, especially methyl.

In the case where R⁵ is a divalent phenylene or C₁ -C₆ alkylene group,such group is bonded to another atom of the ##STR70## ring so as to forma bridged polycyclic ring, e.g a quaternized quinuclidine ring of theformula ##STR71## substituent of formula I represents an optionallysubstituted non-aromatic (which may be fused to another aromatic ornon-aromatic ring) mono-, bi- or polycyclic nitrogen-containingheterocyclic radical attached to substitutent A through a ring nitrogenatom, thereby forming a quaternary ammonium group. The heterocyclicradical may be saturated or unsaturated (with 1-2 double bonds) and maycontain up to two additional hetero atoms in addition to the quaternarynitrogen, such additional hetero atoms being selected from O, S(O)_(m),N, NR¹⁰ or NR¹⁵ R¹⁶ wherein m is O, 1 or 2, R¹⁰ is hydrogen, optionallysubstituted C₁ -C₆ alkyl or optionally substituted phenyl and R¹⁵ andR¹⁶ are each independently optionally substituted C₁ -C₆ alkyl oroptionally substituted phenyl.

In a preferred embodiment ##STR72## represents a non-aromatic 4-7membered, preferably 5- or 6-membered, N-containing heterocyclic ringcontaining 0-2 double bonds and 0-2 additional hetero-atoms selectedfrom O, S(O)_(m), N, NR¹⁰ or NR¹⁵ R¹⁶ wherein m is O, 1 or 2, R¹⁰ ishydrogen, C₁ -C₆ alkyl optionally substituted by 1-2 substituentsindependently selected from -OR³, --NR³ R⁴, --CO₂ R³, oxo, phenyl,fluoro, chloro, bromo, -SO₂ R³ and --CONR³ R⁴ or phenyl optionallysubstituted by 1-3 substituents independently selected from C₁ -C₆alkyl, -OR³, -NR³ R⁴, fluoro, chloro, bromo, --SO₃ R³, --CO₂ R² and-CONR³ R⁴, and R¹⁵ and R¹⁶ are each independently C_(1-C) ₆ alkyloptionally substituted by 1-2 substituents independently selected from--OR³, --NR.sup. 3 R⁴, --CO₂ R³, oxo, phenyl, fluoro, chloro, bromo,--SO₃ R³ and --CONR³ R⁴ or phenyl optionally substituted by 1-3substituents independently selected from C₁ -C₆ alkyl, --OR³, --NR³ R⁴,fluoro, chloro, bromo, --SO₃ R³, --CO₂ R² and -CONR³ R⁴, wherein R³ andR⁴ in such heterocyclic NR¹⁰ and NR¹⁵ R¹⁶ groups are as defined inconnection with the R⁵ substituent. In such preferred embodiment the##STR73## ring may be optionally substituted by 1-3 substituentsindependently selected from

(a) C₁ -C₆ alkyl optionally substituted by 1-2 substituentsindependently selected from fluoro, chloro, bromo, --OR³, --OCOR³,--OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴, --NR³ CONR³ R⁴, --NR³ SO₂ R⁴,--SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ;

(b) C₂ -C₆ alkenyl optionally substituted by 1-2 substituentsindependently selected from fluoro, chloro, bromo, --OR³, --OCOR³,--OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴, --NR³ CONR³ R⁴, --NR³ SO₂ R⁴,--SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ;

(c) C₂ -C₆ alkynyl optionally substituted by 1-2 substituentsindependently selected from fluoro, chloro, bromo, --OR³, --OCOR³,--OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴, --NR³ CONR³ R⁴, --NR³ SO₂ R⁴,--SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ;

(d) C₃ -C₆ cycloalkyl optionally substituted by 1-2 substituentsindependently selected from fluoro, chloro, bromo, --OR³, --OCOR³,--OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴, --NR³ CONR³ R⁴, --NR³ SO₂ R⁴,--SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ;

(e) cycloalkylalkyl having 3-6 carbon atoms in the cycloalkyl ring and1-6 carbon atoms in the alkyl moiety, optionally substituted by 1-2substituents independently selected from fluoro, chloro, bromo, --OR³,--OCOR³, --OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴, --NR³ CONR³ R⁴, --NR³SO₂ R⁴, --SR³, --SO₃ R³ , --CO₂ R³ and --CONR³ R⁴ ;

(f) heteroaryl wherein the hetero atom or atoms are selected from thegroup consisting of 1-4 oxygen, nitrogen or sulfur atoms, optionallysubstituted by 1-2 substituents independently selected from fluoro,chloro, bromo, -OR³, --OCOR³, --OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴,--NR³ CONR³ R⁴, --NR³ SO₂ R⁴, --SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ;preferred heteroaryl radicals are 5- or 6-membered aromatic heterocyclicrings;

(g) heteroaralkyl wherein the hetero atom or atoms are selected from thegroup consisting of 1-4 oxygen, nitrogen or sulfur atoms and the alkylmoiety has 1-6 carbon atoms, optionally substituted by 1-2 substituentsindependently selected from fluoro, chloro, bromo, --OR³, --OCOR³,--OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴, --NR³ CONR³ R⁴, --NR³ SO₂ R⁴,--SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ; preferred heteroaralkyl arethose in which the heteroaryl radical is a 5- or 6-membered aromaticheterocyclic ring and the alkyl moiety has 1-2 carbon atoms;

(h) heterocyclyl wherein the hetero atom or atoms are selected from thegroup consisting of 1-4 oxygen, nitrogen or sulfur atoms, optionallysubstituted by 1-2 substituents independently selected from fluoro,chloro, bromo, -OR³, --OCOR³, --OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴,--NR³ CONR³ R⁴, --NR³ SO₂ R⁴, --SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ;preferred heterocyclyl are 5- or 6-membered saturated or unsaturatedrings;

(i) heterocyclylalkyl wherein the hetero atom or atoms are selected fromthe group consisting of 1-4 oxygen, nitrogen or sulfur atoms and thealkyl moiety has 1-6 carbon atoms, optionally substituted by 1-2substituents independently selected from fluoro, chloro, bromo, --OR³,--OCOR³, --OCONR³ R⁴, oxo, --NR³ R⁴, --NR³ COR⁴, --NR³ CONR³ R⁴, --NR³SO₂ R⁴, --SR³, --SO₃ R³, --CO₂ R³ and --CONR³ R⁴ ; preferredheterocyclylalkyl are those in which the heterocyclyl moiety is a 5- or6-membered saturated or unsaturated ring;

(j) fluoro, chloro or bromo;

(k) --OR³ ;

(l) --OCO₂ R³ ;

(m) --OCOR³ ;

(n) --OCONR³ R⁴ ;

(o) --OSO₂ R³ ;

(p) oxo;

(q) --NR³ R⁴ ;

(r) R³ CONR⁴ --;

(s) --NR³ CO₂ R⁴ ;

(t) --NR³ CONR³ R⁴ ;

(u) --NR³ SO₂ R⁴ ;

(v) --SR³ ; ##STR74## (y) --SO₃ R³ ; (z) --CO₂ R³ ;

(aa) --CONR³ R⁴ ;

(bb) --CN; or

(cc) phenyl optionally substituted by 1-3 fluoro, chloro, bromo, C₁ -C₆alkyl, --OR³, --NR³ R³, --SO₃ R³, --CO₂ R³ or --CONR³ R⁴.

The R³, R⁴ and R⁹ substituents mentioned above are as defined inconnection with substituent R¹.

The ##STR75## ring as defined above is a non-aromatic heterocyclicgroup. This ring, however, may be fused to another ring which may be asaturated or unsaturated carbocyclic ring, preferably a C₄ -C₇carbocyclic ring, a phenyl ring, a 4-7 membered heterocyclic (saturatedor unsaturated) ring containing 1-3 hetero atoms selected from O,S(O)_(m), N, NR¹⁰ or NR¹⁵ R¹⁶ or a 5-6 membered heteroaromatic ringcontaining 1-3 hetero atoms selected from O, S(O)_(m), N, NR¹⁰ or NR¹⁵R¹⁶ in which m, R¹⁰, R¹⁵ and R¹⁶ are as defined above. The fusedcarbocyclic, phenyl, heterocyclic or heteroaromatic ring may beoptionally substituted by 1-3 substituents independently selected fromC₁ -C₆ alkyl, --OR³, --NR³ R⁴, fluoro, chloro, bromo, --SO₃ R³, --CO₂ R³and --CONR³ R⁴ wherein R³ and R⁴ are as defined above.

Within the above-described preferred embodiment, the preferred compoundsare those in which A is ##STR76## Particularly preferred are thecompounds wherein R⁸ is hydrogen and R¹ is ##STR77## especiallycompounds having the absolute configuration 5R, 6S, 8R.

A particularly preferred embodiment of the present invention comprisescompounds of formula I wherein ##STR78## wherein Y is hydrogen, C₁ --C₆alkyl, hydroxy, --SC₁ --C₆ alkyl, carboxyl, carbamoyl, chloro, bromo,iodo, fluoro or phenyl. Within this subclass, the preferred compoundsare those wherein A ##STR79## Particularly preferred are the compoundswherein R⁸ is hydrogen and R¹ is ##STR80## especially compounds havingthe absolute configuration 5R, 6S, 8R.

A still more preferred embodiment of the present invention comprisescompounds of formula I wherein ##STR81## Within this preferred subclass,the preferred compounds are those wherein A is ##STR82## Particularlypreferred are the compounds wherein R⁸ is hydrogen and R¹ is ##STR83##especially compounds having the absolute configuration 5R, 6S, 8R.

A still more preferred embodiment of the present invention comprisescompounds of formula I wherein ##STR84## in which Y is hydrogen, C₁ -C₆alkyl, hydroxy, --S--C₁ --C₆ alkyl, carboxyl, carbamoyl, chloro, bromo,iodo, fluoro or phenyl. Within this preferred subclass, the preferredcompounds are those wherein A is --(CH₂)_(n) in which n is 2, 3 or 4,most preferably those in which A is -13 CH₂ CH₂ -- and wherein either

(a) R¹ and R⁸ taken together represent ##STR85## or (b) R⁸ is hydrogenand R¹ represents hydrogen, CH₃ CH₂ --, ##STR86## Particularly preferredare the compounds wherein R⁸ is hydrogen and R¹ is ##STR87## especiallycompounds having the absolute configuration 5R, 6S, 8R.

A most preferred embodiment of the present invention comprises compoundsof formula I wherein ##STR88## Within this preferred subclass, thepreferred compounds are those wherein A is --(CH₂)_(n) -- in which n is2, 3 or 4, most preferably those in which A is --CH₂ CH₂ -- and whereineither

(a) R¹ and R⁸ taken together represent ##STR89## or (b) R⁸ is hydrogenand R¹ represents hydrogen, CH₃ CH₂ --, ##STR90## Particularly preferredare the compounds wherein R⁸ is hydrogen and R¹ is ##STR91## especiallycompounds having the absolute configuration 5R, 6S, 8R.

The most preferred embodiments of the present invention comprise thecompounds of the formula ##STR92## and R² is hydrogen, an anionic chargeor a conventional readily removable carboxyl protecting group, providingthat when R² is hydrogen or a protecting group, there is also present acounter ion, and pharmaceutically acceptable acid addition saltsthereof.

It will be appreciated that certain products within the scope of formulaI may be formed as optical isomers as well as epimeric mixtures thereof.It is intended that the present invention include within its scope allsuch optical isomers and epimeric mixtures. For example, when the6-substituent is hydroxyethyl, such substituent may be in either the Ror S configuration and the resulting isomers as well as epimericmixtures thereof are encompassed by the present invention.

The carbapenem derivatives of general formula I are prepared fromstarting materials of the formula ##STR93## wherein R¹ and R⁸ aredefined above and wherein R^(2') represents a conventional readilyremovable carboxyl protecting group. Compounds of formula III have beendisclosed, for example, in European Patent Application 38,869 (compound7) and may be prepared by the general methods described therein.

One process for preparing compounds I from starting materials III may besummarized by the following reaction scheme: ##STR94##

To elaborate on the above process, starting material III is reacted inthe inert organic solvent such as methylene chloride, acetonitrile ordimethylformamide with about an equimolar amount of diphenylchlorophosphate in the presence of a base such as diisopropylethylamine,triethylamine, 4-dimethylaminopyridine or the like to give intermediateIV. The acylation to establish the diphenylphosphoryloxy leaving groupat the 2-position of intermediate III is advantageously carried out at atemperature of from about -20° to +40° C., most preferably at about 0°C. Intermediate IV may be isolated if desired, but is conveniently usedfor the next step without isolation or purification.

Intermediate IV is next converted to intermediate V by a conventionaldisplacement reaction. Thus, intermediate IV may be reacted withapproximately an equimolar amount of a mercaptan reagent of the formula

    HS--A--OH

wherein A represents cyclopentylene, cyclohexylene or C₂ -C₆ alkyleneoptionally substituted by one or more C₁ -C₄ alkyl groups in an inertorganic solvent such as dioxane, dimethylformamide, dimethylsulfoxide oracetonitrile and in the presence of a base such asdiisopropylethylamine, triethylamine, sodium hydrogen carbonate,potassium carbonate or 4-dimethylaminopyridine. The temperature for thedisplacement is not critical, but an advantageous temperature range isfrom about -40° C. to 25° C. Most conveniently, the reaction is carriedout with cooling, e.g. at about 0° C.

Intermediate V is then acylated with methanesulfonyl chloride or afunctional acylating equivalent thereof such as methanesulfonic acidanhydride in an inert organic solvent and in the presence of base toprovide the methanesulfonyloxy leaving group of intermediate VI. Theacylation is carried out in an inert organic solvent such astetrahydrofuran, methylene chloride, acetonitrile or dimethylformamideand in the presence of a suitable base such as diisopropylethylamine,triethylamine, 4-dimethylaminopyridine, and the like. The reaction maybe carried out over a wide temperature range, e.g. -40° C. to +40° C.,but is most advantageously conducted with cooling, e.g. at about -30° C.to -40° C.

Intermediate Vi is next subjected to a displacement reaction so as toprovide in intermediate II the iodo leaving group. This particular grouphas been found to greatly facilitate preparation of the carbapenemend-products of formula I.

The displacement of the methanesulfonyloxy leaving group is carried outby reacting intermediate Vi with a source of iodide ions in an inertorganic solvent such as acetone, dimethylformamide or dimethylsulfoxide.Any compound which ionizes in the solvent employed to provide iodideions may be used, e.g. an alkali metal iodide such as NaI or KI. Thetemperature for the displacement is not critical, but temperatures ofroom temperature or above are most advantageous for achieveingcompletion of the reaction in a reasonable time period. The source ofiodide ions is employed in an amount so as to provide approximately anequivalent or excess of iodide ion relative to intermediate VI.

Preparation of the desired carbapenem derivatives of formula I iscarried out by a nucleophilic displacement of the iodo leaving group ofintermediate II by the desired nitrogen-containing heterocyclicnucleophile ##STR95## Intermediate II is reacted with at least anequivalent, preferably an excess, of the desired amine reagent in aninert organic solvent and in the presence of silver ion. Suitable inertorganic solvents include, for example, tetrahydrofuran, dioxane,methylene chloride, diglyme, dimethoxyethane, and the like. Any silvercompound which substantially ionizes in the solvent to give silver ionsand an inert anion may be used as the source of silver ion, e.g. AgClO₄.Generally, we prefer to use approximately an equivalent amount (relativeto intermediate II) of silver ion to facilitate the displacement. Thereaction may be carried out over a wide temperature range, e.g. fromabout -25° to about +25° C., but is most preferably conducted at around0° C. Intermediate I' will have a counter anion (e.g. derived from thesilver salt used) associated with it which may at this stage besubstituted by a different counter anion, e.g. one which ispharmaceutically acceptable, by conventional procedures. Alternatively,the counter ion may be subsequently removed during the de-blocking step.

The de-blocking step to remove the carboxyl protecting group R^(2') ofintermediate I' is accomplished by conventional procedures such assolvolysis, chemical reduction or hydrogenation. Where a protectinggroup such as p-nitrobenzyl, benzyl, benzhydryl or 2-naphthylmethyl isused which can be removed by catalytic hydrogenation, intermediate I' ina suitable solvent such as dioxane-water-ethanol,tetrahydrofuran-diethylether-buffer, tetrahydrofuran-aqueous dipotassiumhydrogen phosphate-isopropanol or the like may be treated under ahydrogen pressure of from 1 to 4 atmospheres in the presence of ahydrogenation catalyst such as palladium on charcoal, palladiumhydroxide, platinum oxide or the like at a temperature of from 0° to 50°C. for from about 0.24 to 4 hours. When R^(2') is a group such aso-nitrobenzyl, photolysis may also be used for deblocking. Protectinggroups such as 2,2,2-trichloroethyl may be removed by mild zincreduction. The allyl protecting group may be removed with a catalystcomprising a mixture of a palladium compound and triphenyl phosphine inan aprotic solvent such as tetrahydrofuran, diethyl ether or methylenechloride. Similarly, other conventional carboxyl protecting groups maybe removed by methods known to those skilled in the art. Finally, asmentioned above, compounds of formula I' where R^(2') is aphysiologically hydrolyzable ester such as acetoxymethyl, phthalidyl,indanyl, pivaloyloxymethyl, methoxymethyl, etc. may be administereddirectly to the host without de-blocking since such esters arehydrolyzed in vivo under physiological conditions.

Preparation of certain compounds of general formula I may involve afurther reaction step just prior to or following the de-blockingreaction. Thus, for example, when the desired heterocyclicnitrogen-containing substituent ##STR96## contains a sulfoxide group,one can first make the corresponding compound having thesulfur-containing heterocycle by the above process and then subject suchcompound, either before or after carboxyl de-blocking, to oxidation soas to form the corresponding sulfoxide end-product.

While the above-described process is suitable for preparing thecompounds of the present invention, out colleague Pierre Dextraze hasinvented a new process which can be used to prepare compounds of formulaI where substituent A is cyclopentylene, cyclohexylene or ##STR97## inwhich R¹¹, R¹², R¹³, and R¹⁴ are each independently hydrogen or C₁ -C₄alkyl. This process, which is disclosed and claimed in a co-pending U.S.Patent Application filed even data with the present continuation-in-partapplication is the preferred process for preparing the above-mentionedclass of compounds.

The alternative process for preparing compounds of Formula I wherein Ais cyclopentylene, cyclohexylene or ##STR98## in which R¹¹, R¹², R¹³ andR¹⁴ are each independently hydrogen or C₁ -C₄ alkyl comprises reactingan intermediate of the formula ##STR99## wherein R¹ and R⁸ are asdefined for the compounds of Formula I and R^(2') is a conventionalreadily removable carboxyl protecting group with a thiol compound of theformula ##STR100## are as defined above in connection with the compoundsof Formula I and X⊖ is a counter anion in an inert solvent and in thepresence of base to produce the carbapenem product of the formula##STR101## and X⊖ are as defined above and, if desired, removing thecarboxyl protecting group R^(2') to give the corresponding de-blockedcompound of Formula I, or a pharmaceutically acceptable salt thereof.

The above alternative process utilizes intermediate IV which may beprepared as described above for the general synthetic process.Intermediate IV is generally prepared in situ from intermediate III andused without isolation or purification.

In the alternative process, carbapenem intermediate IV is reacted with aquaternary amine thiol of the formula ##STR102## wherein A iscyclopentylene, cyclohexylene or ##STR103## in which R¹¹, R¹², R¹³ andR¹⁴ are each independently hydrogen or C₁ -C₄ alkyl, X⊖ is a counteranion associated with a strong acid such as Cl⁻, Br⁻, CH₃ SO₃ ⁻, CF₃ SO₃⁻ or ##STR104## is as defined above. The reaction is carried out in aninert solvent such as acetonitrile, acetonitrile--H₂ O,acetonitrile-dimethylformamide, tetrahydrofuran, tetrahydrofuran--H₂ Oor acetone in the presence of base. The nature of the base is notcritical. Best results, however, have been obtained when anon-nucleophilic tertiary amine base such as diisopropylethylamine,1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene ora tri(C₁ -C₄)alkylamine such as triethylamine, tributylamine ortripropylamine is employed. Reaction of intermediate IV with thiol VIImay be carried out over a wide temperature range, e.g. -15° C. up toroom temperature, but is preferably done at a temperature in the rangeof from about -15° C. to +15° C., most preferably at around 0° C.

The carbapenem product produced by reaction of the quaternary aminethiol VII with intermediate IV will have a counter anion associated withit (i.e. (C₆ H₅ O)₂ PO₂.sup.⊖, Cl.sup.⊖ or the anion associated with thequaternary thiol) which may at this stage be substituted by a differentcounter anion, e.g. one which is more pharmaceutically acceptable, byconventional procedures. Alternatively, the counter anion may be removedduring the subsequent de-blocking step. Where the quaternized carbapenemcompound and counter anion form an insoluble product, the product maycrystallize out as it is formed and be collected pure by filtration.

Following formation of the desired carbapenem product according to theabove-described reaction step, the carboxyl protecting group R^(2') ofcompound I' may be optionally removed by conventional procedures asdescribed above in connection with the general synthetic process.

The thiol intermediates of Formula VII may be prepared, for example, byreacting a sulfide of the formula ##STR105## wherein R¹¹, R¹², R¹³ andR¹⁴ are each independently hydrogen or C₁ -C₄ alkyl with a heterocyclicamine (as defined above) of the formula ##STR106## and a strong acid.The reaction may be carried out in the presence or absence of an inertorganic solvent which is preferably a non-polar organic solvent such asmethylene chloride, benzene, xylene, toluene or the like. Where theamine and sulfide reagents are liquids or where a solid amine is solublein a liquid sulfide reagent, it is preferred to carry out the reactionwithout use of an additional solvent.

The particular strong acid used in the reaction is not critical and maybe, for example, such strong inorganic or organic acids as hydrochloric,hydrobromic, methanesulfonic, p-toluenesulfonic,trifluoromethanesulfonic, etc.

Formation of the quaternary amine thiol intermediate VII may be carriedout at a temperature in the range of from about -20° C. to about 100° C.Preferred temperatures are generally in the range of about 50°-70° C.

The sulfide reagent, aromatic amine and acid are preferably employed sothat the sulfide and acid are used in approximately equimolar amountswith the amine being used in excess, e.g. two of three moles of amineper mole of sulfide or acid.

The quaternary amine thiol intermediate will have a counter anionassociated with it which will be determined by the particular acidemployed. It is, of course, possible to substitute at this point adifferent counter anion by conventional procedures for use in thesubsequent reaction with carbapenem intermediate IV.

It will be understood that where the R¹ and/or R⁸ substituent or theheterocyclic nucleophile attached to substituent A contain a functionalgroup which might interfere with the intended course of reaction, suchgroup may be protected by a conventional blocking group and thensubsequently de-blocked to regenerate the desired functional group.Suitable blocking groups and procedures for introducing and removingsuch groups are well known to those skilled in the art.

In the case of certain compounds of formula I having a cycloalkylene orbranched alkylene A substituent, one or more additional assymmetriccarbon atoms may be created which result in formation ofdiastereoisomers. The present invention includes mixtures of suchdiastereoisomers as well as the individual purified diastereoisomers.

As in the case of other β-lactam antibiotics, compounds of generalformula I may be converted by known procedures to pharmaceuticallyacceptable salts which, for purposes of the present invention, aresubstantially equivalent to the non-salted compounds. Thus, for example,one may dissolve a compound of formula I wherein R² is an anionic chargein a suitable inert solvent and then add an equivalent of apharmaceutically acceptable acid. The desired acid addition salt may berecovered by conventional procedures, e.g. solvent precipitation,lyophilization, etc. Where other basic or acidic functional groups arepresent in the compound of formula I, pharmaceutically acceptable baseaddition salts and acid addition salts may be similarly prepared byknown methods.

A compound of formula I where R² is hydrogen or an anionic charge, or apharmaceutically acceptable salt thereof may also be converted byconventional procedures to a corresponding compound where R² is aphysiologically hydrolyzable ester group, or a compound of formula Iwherein R² is a conventional carboxyl protecting group may be convertedto the corresponding compound where R² is hydrogen, an anionic charge ora physiologically hydrolyzable ester group, or a pharmaceuticallyacceptable salt thereof.

The novel carbapenem derivatives of general formula I wherein R² ishydrogen, an anionic charge or a physiologically hydrolyzable carboxylprotecting group, or the pharmaceutically acceptable salts thereof, arepotent antibiotics active against various gram-positive andgram-negative bacteria and they may be used, for example; as animal feedadditives for promotion of growth, as preservatives in food, asbactericides in industrial applications, for example in waterbased paintand in the white water of paper mills to inhibit the growth of harmfulbacteria and as disinfectants for destroying or inhibiting the growth ofharmful bacteria on medical and dental equipment. They are especiallyuseful, however, in the treatment of infectious disease in humans andother animals caused by gram-positive or gram-positive bacteria.

The pharmaceutically active compounds of this invention may be usedalone or formulated as pharmaceutical compositions comprising, inaddition to the active carbapenem ingredient, a pharmaceuticallyacceptable carrier or diluent. The compounds may be administered by avariety of means; those of principal interest include: orally, topicallyor parenterally (intravenous or intramuscular injection). Thepharmaceutical compositions may be in solid form such as capsules,tablets, powders, etc. or in liquid form such as solutions, suspensionsor emulsions. Compositions for injection, the preferred route ofdelivery, may be prepared in unit dose form in ampules or in multidosecontainers and may contain formulatory agents such as suspending,stabilizing and dispersing agents. The compositions may be in ready touse form or in powder form for reconstitution at the time of deliverywith a suitable vehicle such as sterile water.

The dosage to be administered depends to a large extent on theparticular compound being used, the particular composition formulated,the route of administration, the nature and condition of the host andthe particular situs and organism being treated. Selection of theparticular preferred dosage and route of application, then, is left tothe discretion of the therapist. In general, however, the compounds maybe administered parenterally or orally to mammalian hosts in an amountof from about 5 to 200 mg/kg/day. Administration is generally carriedout in divided doses, e.g. three to four times a day.

To illustrate the potent broad-spectrum antibacterial activity of thecarbapenems of the present invention, both in vitro and in vivo, and thelow toxicity of the compounds, biological data is provided belowrelating to the presently preferred carbapenem compounds of the presentinvention.

In Vitro Activity

A sample of the carbapenem compound of Example 1 after solution in waterand dilution with Nutrient Broth was found to exhibit the followingMinimum Inhibitory Concentrations (M.I.C.) in mcg/ml versus theindicated microorganisms as determined by overnight incubation at 37° C.by tube dilution. N-Formimidoyl thienamycin was included as a comparisoncompound.

    ______________________________________                                        In Vitro                                                                      Antibacterial Activity of Carbapenem                                          Derivative of Example 1                                                                    MIC (mcg/ml)                                                                                 N--Formimidoyl                                    Organism       New Compound Thienamycin                                       ______________________________________                                        S. pneumoniae                                                                           A-9585   0.002        0.004                                         S. pyogenes                                                                             A-9604   0.002        0.001                                         S. aureus A-9537   0.008        0.004                                         S. aureus +                                                                             A-9537   0.016        0.016                                         50% serum                                                                     S. aureus A-9606   0.016        0.008                                         (Pen-res.)                                                                    S. faecalis                                                                             A20688   1            0.5                                           E. coli   A15119   0.03         0.016                                         E. coli   A20341-1 0.03         0.03                                          K. pneumoniae                                                                           A-9664   0.06         0.13                                          K. pneumoniae                                                                           A20468   0.13         0.06                                          P. mirabilis                                                                            A-9900   0.13         0.06                                          P. vulgaris                                                                             A21559   0.03         0.03                                          P. morganii                                                                             A15153   0.13         0.13                                          P. rettgeri                                                                             A22424   0.25         0.25                                          S. marcescens                                                                           A20019   0.06         0.03                                          E. cloacae                                                                              A-9569   0.25         0.06                                          E. cloacae                                                                              A-9656   0.13         0.06                                          P. aeruginosa                                                                           A-9843A  4            1                                             P. aeruginosa                                                                           A21213   0.25         0.25                                          B. fragilis                                                                             A22862   0.13         0.016                                         B. fragilis                                                                             A22053   0.25         0.06                                          B. fragilis                                                                             A22696   0.5          0.13                                          B. fragilis                                                                             A22863   0.13         1                                             ______________________________________                                    

In Vivo Activity

The in vivo therapeutic efficacy of the compound of Example 1 andN-formimidoyl thienamycin after intramuscular administration to miceexperimentally infected with various organisms is shown in the followingTable. The PD₅₀ (dose in mg/kg required to give protection to 50% of theinfected mice) is indicated.

    ______________________________________                                        Protective Effect in the Intramuscular                                        Treatment of Infected Mice                                                            Challenge                                                                             PD.sub.50 /Treatment (mg/kg)                                            (No. of   Compound of N--Formimidoyl                                Organism  organisms)                                                                              Example 1   Thienamycin                                   ______________________________________                                        P. mirabilis                                                                            4 × 10.sup.6                                                                      >10         3*/15*                                        A-9900                                                                        P. aeruginosa                                                                           3 × 10.sup.6                                                                        3         0.5*                                          A-9843a                                                                       ______________________________________                                         *Historical data                                                         

Treatment Schedule: Mice were treated i.m. with drugs 0 and 2 hourspost-infection; 5 mice per dose were used for each test

Toxicity

The toxicity of the compound of Example 1 after intracranialadministration to mice was determined and is shown in the followingTable.

    ______________________________________                                        Toxicity After Intracranial                                                   Administration to Mice                                                                               Highest Dose (mg/kg)                                                 *LD.sub.50                                                                             Without Clinical                                       Compound      (mg/kg)  Signs of Toxicity                                      ______________________________________                                        Compound of   >10      >10                                                    Example 1                                                                     N--Formimidoyl                                                                               32       ˜5                                              Thienamycin                                                                   ______________________________________                                         *Average of 25/mice/compound                                             

Blood Levels in Mice After Intramuscular Administration

Blood levels and the half-life of the compound of Example 1 afterintramuscular administration of 20 mg/kg in mice are shown in the Tablebelow.

    ______________________________________                                        Blood Level (μg/ml)          **AUC                                         10         20     30    45  60   90   *t.sub.1/2                                                                          (μg · h/              Compound                                                                              Minutes after Administration                                                                      (min)   ml)                                       ______________________________________                                        Compound                                                                              13.7   10.2   5.7 2.1 <0.6 <0.6 11    5.4                             of Example                                                                    N--Formi-                                                                             12.6    9.9   7.3 2.6  0.7 <0.3  9    6                               midoyl                                                                        Thien-                                                                        amycin                                                                        ______________________________________                                         Compounds were solubilized in 0.1 M phosphate buffer pH 7. Values are fro     a single test; 4 mice used per compound.                                      *t.sub.1/2  refers to halflife in minutes                                     **AUC refers to the area under the blood concentrationtime curve         

The urinary recovery of the compound of Example 1 after intramuscularadministration (20 mg/kg) to mice is shown in the following Table.

    ______________________________________                                        Urinary Recovery After                                                        Intramuscular Administration                                                  of 20 mg/kg to Mice                                                                       Percentage of Dose Recovered                                                  0-3  3-6      6-24   0-24                                         Compound      Hours After Administration                                      ______________________________________                                        Compound of   18.8   0.6       0.1 19.5 ± 3.2                              Example 1                                                                     N--Formimidoyl                                                                              12.1   0.1      <0.1 12.2 ± 3.6                              Thienamycin                                                                   ______________________________________                                         Compounds were solubilized in 0.1 M phosphate buffer pH 7. Values are fro     a single test; 4 mice per compound.                                      

Compounds were solubilized in 0.1 M phosphate buffer pH 7. Values arefrom a single test; 4 mice per compound.

Additional Biological Data In Vitro Activity

Samples of the carbapenem compounds indicated below (identified byexample number) after solution in water and dilution with Nutrient Brothwere found to exhibit the following Minimum Inhibitory Concentrations(M.I.C.) in mcg/ml versus the indicated microorganisms as determined byovernight incubation at 37° C. by tube dilution. N-formimidoylthienamycin was included as a comparison compound.

    __________________________________________________________________________                   MIC (μg/ml)                                                                Compound (Example No.)                                                                              Ex. 5 Ex. 5                              Organism       Ex. 2                                                                             MK 0787                                                                            Ex. 3                                                                            *MK 0787                                                                            Ex. 4                                                                             (comp. B)                                                                           (comp. A)                                                                           *MK 0787                     __________________________________________________________________________    S. pneumoniae                                                                           A-9585                                                                             0.001                                                                              0.002                                                                             0.03                                                                              0.002                                                                              0.004                                                                             0.004 0.004  0.001                       S. pyogenes                                                                             A-9604                                                                             0.002                                                                              0.002                                                                             0.03                                                                              0.002                                                                              0.004                                                                             0.008 0.004  0.001                       S. faecalis                                                                             A20688                                                                             0.25                                                                              0.25 0.5                                                                              0.5   2   1     0.05  0.25                         S. aureus A-9537                                                                             0.008                                                                              0.002                                                                             0.03                                                                              0.004                                                                              0.03                                                                              0.03  0.016  0.002                       S. aureus-50% serum                                                                     A-9537                                                                             0.016                                                                              0.016                                                                             0.13                                                                              0.016                                                                              0.06                                                                              0.06  0.03   0.004                       S. aureus (Pen-res.)                                                                    A-9606                                                                             0.016                                                                              0.008                                                                             0.03                                                                              0.008                                                                              0.06                                                                              0.06  0.03   0.004                       E. coli   A15119                                                                             0.016                                                                              0.016                                                                             0.03                                                                              0.016                                                                              0.13                                                                              0.13  0.03   0.016                       E. coli   A20341-1                                                                           0.03                                                                               0.016                                                                             0.03                                                                             0.03  0.13                                                                              0.13  0.03   0.016                       K. pneumoniae                                                                           A-9664                                                                             0.06                                                                              0.03 0.13                                                                             0.06  0.25                                                                              0.25  0.06  0.03                         K. pneumoniae                                                                           A20468                                                                             0.13                                                                              0.13 0.25                                                                             0.13  0.5 0.5   0.13  0.06                         E. cloacae                                                                              A-9659                                                                             0.13                                                                              0.13 0.25                                                                             0.06  1   0.5   0.13  0.06                         E. cloacae                                                                              A-9656                                                                             0.13                                                                              0.06 0.5                                                                              0.06  2   0.25  0.13  0.06                         P. mirabilis                                                                            A-9900                                                                             0.06                                                                              0.03 0.13                                                                             0.06  0.25                                                                              0.25  0.13  0.03                         P. vulgaris                                                                             A21559                                                                             0.03                                                                               0.016                                                                             0.03                                                                             0.03  0.25                                                                              0.25  0.06   0.016                       M. morganii                                                                             A15153                                                                             0.06                                                                              0.06 0.13                                                                             0.13  1   0.5   0.13  0.06                         P. rettgeri                                                                             A22424                                                                             0.13                                                                              0.13 0.5                                                                              0.13  1   1     0.25  0.13                         S. marcescens                                                                           A20019                                                                             0.06                                                                              0.03 0.06                                                                             0.03  0.25                                                                              0.25  0.06  0.03                         P. aeruginosa                                                                           A-9843a                                                                            32  1    63 1     16  63    32    1                            P. aeruginosa                                                                           A21213                                                                             8   0.13 8  0.25  1   32    16    0.13                         __________________________________________________________________________     *N--formimidoyl thienamycin                                              

In Vivo Activity

The in vivo therapeutic efficacy of certain compounds of the presentinvention and N-formimidoyl thienamycin (MK 0787) after intramuscularadministration to mice experimentally infected with various organisms isshown below. The PD₅₀ (dose in mg/kg required to give protection to 50%of the infected mice) is indicated.

    ______________________________________                                        Protective Effect in the Intramuscular                                        Treatment of Infected Mice                                                            PD.sub.50 /treatment (mg/kg)                                          Compound  P. aeruginosa                                                                              P. aeruginosa                                                                            S. aureus                                   (Example No.)                                                                           *A9843A      *A20481    *A-9606                                     ______________________________________                                        Ex. 2     4.7          33         0.72                                        Ex. 5 comp. B                                                                           --           --         0.39                                        Ex. 5 comp. A                                                                           >12.5        --         1.2                                         Ex. 4     2.7          --         1.6                                         MK 0787   1            0.4        0.07                                        ______________________________________                                         Treatment Schedule:                                                           *For compound of Ex. 2, mice were infected i.p. with 2 × 10.sup.9       organisms (A9606), or 1 × 10.sup.5 of A9843A and A20481. For            compounds of Ex. 4 and 5, mice were infected i.p. with ˜9 ×       10.sup.7 organisms (A9606) or ˜8 × 10.sup.4 (A9843A). Mice        were treated i.m. with drugs 0 and 2 h postinfection.                    

Blood Levels and Urinary Recovery

Blood levels and the half-life of certain compounds of the presentinvention after intramuscular administration of 20 mg/kg in mice areshown below. Also shown is the urinary recovery in the mice.

    ______________________________________                                        Pharmacokinetic Parameters in the Mouse After                                 Intramuscular Dose of 20 mg/kg                                                        Blood             Urine                                               Compound  C.sub.max                                                                              *T.sub.1/2                                                                             **AUC   Recovery***                               (Example No.)                                                                           (μg/ml)                                                                             (min)    (μg · h/ml)                                                               %                                         ______________________________________                                        Ex. 3     16.2      8       4.8     15 ± 3                                 Ex. 4     17.3     12       7.6      33 ± 11                               Ex. 5 comp. A                                                                           10.2      7       3.1     14 ± 1                                 Ex. 5 comp. B                                                                           12.6     10       4.6     15 ± 3                                 MK 0787   14.6     10       6       33 ± 8                                 ______________________________________                                         Compounds were solubilized in 0.1 M phosphate buffer, pH 7.                   Values based on a single test; 4 mice per compound.                           *T.sub.1/2 refers to halflife in minutes                                      **AUC refers to the area under the blood concentrationtime curve               ***Recovery based on 0-6 hour collection                                

EXAMPLE 1 Preparation of3-[2-(N-methylpyrrolidinium)ethylthio]-6α-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate ##STR107## A. p-Nitrobenzyl3-(2-hydroxyethylthio)-6α-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate ##STR108##

A solution of 1.69 g (4.85 mmol) of p-nitrobenzyl6α-[1-(R)-hydroxyethyl]-3,7-dioxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylate (1) in 20 ml of acetonitrile was cooledto 0° C. under a nitrogen atmosphere. A solution of 726 mg (7.18 mmol)of diisopropylethylamine in 2 ml of acetonitrile was added followed by adropwise addition of 1.51 g (5.60 mmol) of diphenyl chlorophosphate in12 ml of acetonitrile over a period of 3 minutes. The resulting solutionwas stirred at 0° for 20 minutes to provide p-nitrobenzyl3-(diphenylphosphoryloxy)-6α-(R)-hydroxyethyl]-7-oxo-1-azabicyclo-(3.2.0)hept-2-ene-2-carboxylate.To this solution was added a solution of 726 mg (7.18 mmol) ofdiisopropylethylamine in 2 ml of acetonitrile followed by a solution of439 mg (5.63 mmol) of 2-mercaptoethanol in 2 ml of acetonitrile. Thereaction solution was stirred at 0° C. for 3 hours and then diluted with200 ml of ethyl acetate and washed with 200 ml of water, 100 ml of 20%aqueous H₃ PO₄, and brine. Evaporation of the dried (MgSO₄) solutiongave a semisolid which was triturated with methylene chloride andfiltered to yield 1.2 g (61% yield) of title product 2 as a whiteamorphous solid.

NMR (DMSO-d6) δ:1.20 (3H, d, J=6.0 Hz), 2.9--3.2 (9H, m), 5.22 (1H, d,J=8.5 Hz) and 8.23 (2H, d, J=8.5 Hz); ir (KBr) γmax: 3500, 1770 and 1700cm⁻¹ ;

Anal. Calc'd for C₁₈ H₂₀ N₂ O₇ S: C, 52.93; H, 4.94; N, 6.86; S, 7.85.Found: C, 52.83; H, 4.90; N, 6.42; S, 8.31.

B. p-Nitrobenzyl3-(2-methanesulfonyloxyethylthio)-6α-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylate ##STR109##

To a solution of 4.2 g (10.3 mmol) of 2 in 200 ml of tetrahydrofuranthere was added at -40° C. 1.3 g (11.3 mmol) of methanesulfonyl chloridefollowed by a dropwise addition of 1.26 g (12.4 mmol) of triethylaminein 5 ml of tetrahydrofuran. The reaction mixture was stirred for 5 hoursat -40° C., then stirred for 2 hours at -30° C. under a nitrogenatmosphere and then poured into a mixture of ethyl acetate (700 ml) and5% aqueous phosphoric acid (1000 ml). The organic layer was washed withbrine, dried over MgSO₄, filtered and condensed to a syrup. Thismaterial was purified by silica gel column chromatography [elution withmethylene chloride-ethyl acetate (3:1 v/v)] to give 3.55 g (75% yield)of the title compound as a white amorphous solid.

NMR (CDCl₃) δ: 1.25 (3H, d, J=6.0 Hz), 3.05 (3H, s), 3.06-3.40 (5H, m),4.05-4.40 (4H, m), 5.25 (1H, d, J=14.0 Hz), 5.50 (1H, d, J=14.0 Hz),7.70 (2H, d, J=8.5 Hz) and 8.23 (2H, d, J=8.5 Hz); ir (KBr) γmax: 3400,1770 and 1600 cm⁻¹.

Anal. Calc'd for C₁₉ H₂₂ N₂ O₉ S₂ : C, 46.90; H, 4.56; N, 5.76. Found:C, 46.52; H, 4.32; N, 5.91.

C. p-Nitrobenzyl3-(2-iodoethylthio)-6α-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylate ##STR110##

A solution of 350 mg (0.72 mmol) of intermediate 3 and 216 mg (1.4 mmol)of sodium iodide in 20 ml of acetone was heated at reflux for 4 hours.Evaporation of the acetone gave a white amorphous solid which wassuspended in ether (10 ml)-water (10 ml). Filtration of the white solidand vacuum drying produced 300 mg

(80% yield) of the title compound 4 as a white amorphous powder. NMR(DMSO-d6) δ: 1.18 (3H, d, J=6.0 Hz), 3.20-3.60 (7H, m), 3.80-4.25 (2H,m), 5.10 (1H, d, J=5.5 Hz), 5.25 (1H, d, J=12.0 Hz), 5.45 (1H, d, J=12.0Hz), 7.70 (2H, d, J=8.5 Hz), and 8.27 (2H, d, J=8.5 Hz); ir (KBr) γmax:3500, 1768 and 1700 cm⁻¹ ;

Anal. Calc'd for C₁₈ H₁₉ N₂ O₆ I: C, 41.71; H, 3.70; N, 5.41; I, 24.48.

Found: C, 42.10; H, 3.75; N, 5.97; I, 23.20.

D.3-[2-(N-methylpyrrolidinium)ethylthio]-6α-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate ##STR111##

To a cooled (5° C.) solution of p-nitrobenzyl3-(2-iodoethylthio)-6α-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo-[3.2.0]hept-2-ene-2-carboxylate(728 mg; 1.4 mmol) in 60 ml of dry tetrahydrofuran, there was addedN-methylpyrrolidine (301 mg; 3.5 mmol) followed by a solution of silverperchlorate (560 mg; 2.8 mmol) in 5 ml of tetrahydrofuran. The reactionmixture was stirred for 60 minutes at 5° C. The solvent was thenevaporated in vacuo affording compound 5 as a yellow gum. This gum wasdigested with 2 g of CELITE to give an amorphous solid. IR(KBr) γmax:3400, 1775, 1700 and 1100 cm⁻¹. Without any further purifcation,compound 5 was hydrogenated as follows:

To a suspended solution of compound 5 in 50 ml of diethyl ether and 100ml of tetrahydrofuran, there was added a solution of potassiumbicarbonate (320 mg; 3.2 mmol) and dibasic potassium phosphate (280 mg;1.6 mmol) in 125 ml of water. Then, 1 g of 10% palladium on charcoal wasadded and the mixture was hydrogenated at 40 psi on the Parr shaker for60 minutes. The mixture was then filtered and the catalyst was washedwith water (2×10 ml). The combined filtrate and washing was extractedwith diethyl ether (2×200 ml) and then lyophilized to give a brownpowder. This crude material was purified on a C₁₈ BONDAPAK reverse phasecolumn (8 g) (Waters Associates), eluting with water under a 8 psipressure. Each fraction (20 ml) was screened by high pressure liquidchromatography, and fractions having an ultraviolet absorption λ_(max)300 nm were collected and lyophilized to give 65 mg (14% yield based oncompound 4) of title compound as a white solid.

NMR (D₂ O) δ: 1.23 (3H, d, J=6.0 Hz), 2.1-2.4 (4H, m), 3.10 (3H, s),3.1-3.4 (12 H, m), 3.95-4.30 (2H, m); IR (KBr)γmax: 3400, 1760 and 1590cm⁻¹. UVλ_(max) (CH₃ CH₂ OH) 297 nm (E=6877).

EXAMPLE 2 Preparation of3-[2-(N-Methyl-thiomorpholinium)ethylthio]-6α-[1'-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylate##STR112## A. N- methyl-N-(2-mercaptoethyl)-thiomorpholiniummethanesulfonate ##STR113##

To precooled (ice bath) N-methylthiomorpholine* (500 g, 42.7 mmol) wasadded methanesulfonic acid (1.47 mL, 20.5 mmol) and ethylene sulfide(1.30 mL, 21.4 mmol). The mixture was heated at 65° C. for 24 h anddiluted with water (25 mL). The aqueous solution was washed with diethylether (3×25 mL), pumped under vacuum and poured over a silica gelreverse phase column; the title compound being eluted with water. Theappropriate fractions were combined and evaporated to afford the thiolas an oil (4.80 g, yield 86%); ir (film) ν_(max) : 2550 cm⁻¹ (w,SH); ¹Hmr (DMSO d₆)δ: 3.25-2.95 (6H, m, CH₂ N.sup.⊕), 3.32 (3H, s, CH₃N.sup.⊕), 3.20-2.65 (7H, m, CH₂ S, SH) and 2.32 ppm (3H, s, CH₃ SO₃).

B. para-Nitrobenzyl 3-[2-(N-methyl-thiomorphonilium diphenyl phosphate)ethylthio]-6α-[1'-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylate##STR114##

A cold (ice bath) solution of para-nitrobenzyl6α-[1'-(R)-hydroxyethyl]-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylate(557 mg, 1.60 mmol) in CH₃ CN (8 mL) was treated dropwise withdiisopropylethyl amine (0.336 mL, 1.92 mmol) and diphenylchlorophosphate(0.400 mL, 1.92 mmol) and stirred for 30 min. The reaction mixture wastreated again with N-methyl-N-(2-mercaptoethyl)thiomorpholiniummethanesulfonate (893 mg, 2.29 mmol) in CH₃ CN (4 mL) anddiisopropylethyl amine (0.336 mL, 1.92 mmol) and stirred for 30 min. Thesolution was diluted with water (20 mL) and poured over a silica gelreversed phase column. The desired compound was eluted with a 50%acetonitrile-water mixture. The appropriate fractions were combined,pumped under vacuum for 2 h. and lyophylized to afford the titlecompound (1.01 g, yield 85%): ir (nujol)ν_(max) : 1760 (s, β-lactam C=O)and 1510 cm⁻¹ (s, NO₂); ¹ Hmr (DMSO-d₆) δ: 8.25 (2H, d, J=8.8 Hz,H-aromatic), 7.70 (2H, d, J=8.8 Hz, H-aromatic), 7.33-6.84 (10 H, m,H-aromatic), 5.37 (2H, center of ABq, J=14.2 Hz, CH₂), 5.14 (1H, d,J=4.5 Hz, OH), 4.35-3.80 (2H, m, H-1' and H-5), 3.75-3.45 (6H, m, CH₂N³⁰), 3.31 (3H, s, CH₃ N⁺), 3.45-2.75 (9H, m, CH₂ S, H-6 and H-4) and1.15 ppm (3H, d, J=6.2 Hz, CH₃).

C.3-[2-(N-methyl-thiomorpholinium)ethylthio]-6α--[1'-(R)-hydroxyethy]-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylate##STR115##

A solution of para-nitrobenzyl 3-[2-(N-methylthiomorpholiniumdiphenylphosphate)ethylthio]-6α-[1'-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate(1.31 g, 1.76 mmol) in 0.1 M pH 7.4 phosphate buffer (48.8 mL),tetrahydrofuran (20 mL) and diethyl ether (20 mL) was hydrogenated over10% pd/C (1.5 g) in a Parr shaker for 1 h at 40 psi. The reactionmixture was diluted with diethyl ether (40 mL) and the phases wereseparated. The organic phase was washed with water (2×5 mL). The aqueousphases were combined, filtered through a #52 hardened filter paper,washed with diethyl ether (2×20 mL) and pumped under vacuum. The aqueoussolution was poured on a silica gel reverse phase column and the desiredcarbapenem was eluted with 5% acetonitrile-water. The appropriatefractions were combined, and lyophilized to give title compound as anamorphous solid (205 mg, 31%); ir (nujol)ν_(max) : 1750 (s, β-lactamC=O) and 1590 cm⁻¹ (s, C=O); ¹ Hmr (D₂ O) δ:4.25-3.95 (2H, m, H-1',H-5), 3.70-3.40 (6H, m, CH₂ N⁺), 3.35 (1H, dd, J=6.1 Hz, J=2.6 Hz, H-6),3.08 (3H, s, CH₃ N⁺), 3.25-2.75 (8H, CH₂ S, H-4), and 1.24 ppm (3H, d,J=6.4 Hz, CH₃); uv (H₂ O, c 0.062)λ_(max) : 299 (ε10,962) T1/2 17.7 h(0.1 M pH 7 phosphate buffer, 37° C.).

EXAMPLE 3 Preparation of(5R,6S)-3-[2-(1-methylmorpholino)ethylthio]-6-[(R)-1-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate##STR116## A. 1-Methyl-1-(2-mercaptoethyl)morpholiniumtrifluoromethanesulfonate ##STR117##

To N-methylmorpholine (3.29 mL, 0.030 mol) was added dropwisetrifluoromethanesulfonic acid (1.327 mL, 0.015 mol) at 10° C., followedby ethylene sulfide (0.89 mL, 0.015 mol). The resulting yellow-brownsolution was heated (oil bath) at 50°-60° C. under N₂ for 18 h. Volatilematerial was then removed in vacuo and the residual oil was taken up in10 mL of H₂ O. The aqueous solution was washed with diethyl ether (3×5mL) and then residual organic solvent was removed in vacuo. Theresulting aqueous solution was applied to a C₁₈ reverse-phase columnwhich was eluted with H₂ O, then 5% acetonitrile-H₂ O and finally 10%acetonitrile-H₂ O. Evaporation of the relevant fractions afforded awhite solid which was dried in vacuo (P₂ O₅) to give the product (1.92g, 41%). ir (KBr)ν_(max) : 2560 (--SH) cm⁻¹ ; ¹ Hnmr (d₆ -acetone) δ:4.25-3.6 (m, 8H), 3.49 (s, 3H, N-Me), 3.35-2.7 (m, 5H).

B. p-Nitrobenzyl(5R,6S)-3-[2-(1-methylmorpholino)ethylthio]-6-[(R)-1-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatediphenylphosphate ##STR118##

To a solution of p-nitrobenzyl(5R,6S)-6-[(R)-1-hydroxyethyl]-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-carboxylate(0.348 g, 1.0 mmol) in 25 mL of dry acetonitrile was added dropwisediisopropylethylamine (0.191 mL, 1.1 mmol) and then diphenylchlorophosphate (0.228 mL, 1.1 mmol) at 0° C. under N₂. After stirringat 0° C. for 1 h diisopropylethylamine (0.226 mL, 1.3 mmol) was added tothe resulting enol phosphate, followed by1-methyl-1-(2-mercaptoethyl)morpholinium /trifluoromethanesulfonate(0.373 g, 1.2 mmol). The reaction mixture was stirred at roomtemperature for 1.5 h and then concentrated in vacuo. The residualmaterial was taken up in H₂ O and applied to a C₁₈ reverse-phase column.Elution with H₂ O, then 20% acetonitrile-H₂ O and finally 30%acetonitrile-H₂ O followed by lyophilization of the relevant fractionsgave the product (0.360 g, 40%) as an amorphous solid. ir (film) 3300(--OH), 1770 (β-lactam CO), 1700 (--CO₂ PNB) cm⁻¹ ; ¹ Hnmr (d₆ -acetone)δ: 8.25, 7.80 (ABq, J=8.6 Hz, 4H, aromatic), 7.4-6.8 (m, 10H,diphenylphosphate), 5.56, 5.27 (ABq, J=14.2 Hz, 2H, benzylic), 4.42 (dof t, J=9.2 Hz, J'=2.7 Hz, 1H, H-5), 4.1-2.7 (m, 17H), 3.40 (s, 3H,N-Me), 1.22 (d, J=6.2 Hz, 3H, --CHMe).

C.(5R,6S)-3-[2-(1-methylmorpholino)ethylthio]-6-[(R)-1-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate##STR119##

To a solution of p-nitrobenzyl(5R,6S)-3-[2-(1-methylmorpholino)ethylthio]-6-[(R)-1-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatediphenylphosphate (0.360 g, 0.49 mmol) in 13 mL of phosphate buffer(0.05 M pH 7.4) was added 0.36 g of 10% palladium-on-charcoal, 20 mL oftetrahydrofuran and 20 mL of diethyl ether. This mixture washydrogenated (Parr) at 32 psi for 1 h. The mixture was filtered throughCelite and the filter pad was washed with H₂ O and diethyl ether. Theaqueous phase was separated and the pH was adjusted to 7.0 withadditional pH 7.4 phosphate buffer. After removing residual organicsolvents in vacuo the aqueous solution was applied to a C₁₈reverse-phase column. Elution with H₂ O and lyophilization of therelevant fractions afforded 0.130 g of an amorphous solid. This materialwas repurified by reverse-phase hplc to give the pure product (0.058 g,34%) as an amorphous solid. ir (KBr)ν_(max) : 3420 (br, OH), 1750(β-lactam CO), 1590 (--CO₂ ⁻) cm⁻¹ ; ¹ Hnmr (D₂ O) δ: 4.35-2.77 (m,17H),3.18 (s, 3H, N-Me), 1.23 (d, J=6.3 Hz, 3H, CHMe); uv (H₂ O)λ_(max): 300 (ε6344) nm; t_(1/2) (pH 7.4, 36.8° C.) 18.5 h.

EXAMPLE 4 Preparation of(5R,6S)3-[2-(1,4-dimethyl-1-piperazinium)-ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo-[3.2.0]hept-2-ene-2-carboxylate##STR120## A. 1-(2-acetylthioethyl)-1,4-dimethylpiperazinium bromide##STR121##

A solution of 2-bromoethyl thiolacetate *(2.20 g, 0.012 mol) and1,4-dimethylpiperazine (1.95 mL, 0.014 mol) in acetone (4 mL) wasstirred at 50° C. for 65 h. After cooling to 25° C., the liquid phasewas decanted from the gum which was triturated twice in diethyl ether; ahygroscopic yellowish powder, 3.2 g (90%) was obtained; ir (Nujol)ν_(max) : 1685 (C=O of thioester) cm⁻¹ ; ¹ Hmr (D₂ O) δ: 2.37, 2.39##STR122##

B. 1,4-dimethyl-1-(2-mercaptoethyl)piperazinium bromide hydrochloride##STR123##

A solution of 1-(2-acetylthioethyl)-1,4-dimethylpiperazinium bromide(1.1 g, 3.7 mmol) in 6N hydrochloric acid (4 mL) was heated at 80° C.under a nitrogen atomsphere for 1 h. The solution was concentrated underreduced pressure to give a white powder, 0.41 g (38%), ¹ Hmr (DMSO, d₆)δ: 2.90 (s, ##STR124##

Anal. calcd. for C₈ H₂₀ N₂ SBrCl·H₂ O: C 31.03, H 7.16, N 9.05, S 10.35;found: C₃₁.62, H 7.46, N 9.19, S 10.19.

C (5R,6S)Paranitrobenzyl3-[2-(1,4-dimethyl-1-piperazinium)-ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]-hept-2-ene-2-carboxylatediphenylphosphate ##STR125##

To a cold (0° C.) solution of (5R,6S) paranitrobenzyl6-[1-(R)-hydroxyethyl]-3,7-dioxo-1-azabicyclo[3.2.0]heptane-2-(R)-carboxylate(0.465 g, 1.33 mmol) in acetonitrile (2 mL) kept under a nitrogenatmosphere was added diisopropylethylamine (0.278 mL, 1.59 mmol) anddiphenyl chlorophosphate (0.33 mL, 1.59 mmol). The reaction mixture wasstirred for 30 min and treated with a suspension of1,4-dimethyl-1-(2-mercaptoethyl)-piperazinium (3 mL)-water (1 mL)mixture and diisopropylethylamine (0.278 mL, 1.59 mmol). After stirringfor 18 h at 5° C., cold water (15 mL) was added to the mixture. Theresulting solution was chromatographed over PrepPak-500/C₁₈ (WaterAssociates) column (2.5×7.5 cm) with 25-35% acetonitrile in water aseluting solvents to give a yellowish powder 0.50 g (50%) afterlyophylization; ir (KBr)ν_(max) : 1765 (C=O of β-lactam), 1690 (C=O ofPNB ester), 1585 (phenyl), 1512 (NO₂), 875 (NO₂)cm⁻¹, ¹ Hmr (DMSO, d₆)δ: 1.16, 1.18 (2d, J=6.1 Hz, 3H, CH₃ CHOH), 2.44 ##STR126## 5.31 (d, J=6Hz, OH), 5.39 (center of ABq, J=13 Hz, CH₂ of PNB), 6.6-7.4 (m, 10H,phenyl of phosphate), 7.71 (d, J=8.8 Hz, 2H, Ho of PNB), 8.26 (d, J=8.8Hz), Hm of PNB).

D.(5R,6S)3-[2-(1,4-dimethyl-1-piperazinium)ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate##STR127##

To a solution of (5R,6S)paranitrobenzyl3-[2-(1,4-dimethyl-1-piperazinium)ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylatediphenylphosphate (0.47 g, 0.623 mmol) in wet tetrahydrofuran (25 mL)was added diethyl ether (25 mL), potassium phosphate monobasic-sodiumhydroxide buffer (13 mL, pH 7.22) and 10% palladium on charcoal (0.47g). The resulting mixture was hydrogenated at 23° C. under 40 psi for 1h. The two layers were separated and the organic layer was extractedwith water (2×7 mL). The aqueous layers were combined, filtered througha Celite pad, washed with diethylether (2×15 mL) and chromatographed onPrepPak-500 /C₁₈ (Waters Associates) column (2.5×9.5 cm) with water aseluting solvent to give, 0.097 g (43%) after lyophylization; ir (KBr)ν_(max) : 3000-3700 (OH), 1750 (C=O of β-lactam), 1585(carboxylate)cm.sup. -1, ¹ Hmr (D₂ O) β: 1.24 (d, J=6.4 Hz, 3H, CH₃CHOH), 2.33 (s, 3H, ##STR128## 4.0-4.5 (m, H-5, CH₃ CHOH), uv (H₂ O)λ_(max) : 296 (ε9476), [α] _(D) 61.1° (C 0.26, H₂ O), t1/2=12.4 h(measured at a concentration of 10⁻⁴ M in phosphate buffer pH 7.4 at36.8° C.).

EXAMPLE 5 Preparation of(5R,6S)-3-[2-(N-methyl-thiomorpholiniumoxide)ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)-hept-2-ene-2-carboxylate##STR129##

To a cold (-10° C.) solution of (5R,6S)-3-[2-(N-methyl-thiomorpholinium)ethylthio]-6-[1-(R)-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)-hept-2-ene-2-carboxylate(608 mg, 1.65 mmol) in a 1:1 mixture of acetonitrile-water (9 mL) wasadded m-chloroperbenzoic acid (334.8 mg, 1.65 mmol) in small portionover a 1 hour period. The mixture was then diluted with water (15 mL)and washed with diethyl ether (3×15 mL). The aqueous phase was pumpedunder vacuum and passed through a reversed phase silica gel column (H₂O) to give a solid which consisted of a mixture of compounds. Thismixture was separated by reversed phase HPLC and afforded fraction A52.4 mg (yield 12%) and fraction B 23.6 mg (yield 6%) as diastereomersof the title compound; Fraction A: ir (nujol) ν_(max) : 1750 (s,β-lactam C=O) and 1580 cm-1 (s, C=O); ¹ Hmr (D₂ O) δ: 4.26-2.91 (20 H,m, H-4, H-5, H-6, H-1', CH₂ S, CH₂ --O, CH₃ -N⁺ and CH₂ N⁺) and 1.24 ppm(3H, d, J=6.4 Hz, CH₃); uv (H₂ O, c 0.06) λ_(max) : 302 (ε10425); T 1/2:12 h (0.065 M, pH 7.4 phosphate buffer, 37° C.). Fraction B: ir (nujol)ν_(max) : 1750 (s, β-lactam C=O) and 1585 cm-1 (s, C=O); ¹ Hmr (D₂ O)δ3.86-2.90 (17 H, m, H-4, H-5, H-6, H-1', CH₂ S, CH₂ S-O, CH₂ N⁺), 3.25(3H, s, CH₃ N⁺) and 1.24 ppm (3H, d, J=6.4 Hz, CH₃); uv (H₂ O, c 0.05)λ_(max) : 2.99 (ε6517); T 1/2:10.75 h (0.065 M, pH 7.4 buffer solution,37° C.).

EXAMPLE 6 Preparation of(5R,6S)-3-[2-(1,4,4-Trimethyl-1-piperazinium)-ethylthio]-6-(1R-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylatechloride ##STR130## A. 1-(2-acetylthioethyl)-1,4,4-trimethylpiperaziniumbromideiodide ##STR131##

A suspension of 1-(2-acetylthioethyl)-1,4-dimethylpiperazinium bromide(1.48 g, 5.0 mmol) is isopropyl alcohol (10 mL) was treated withmethyliodide (0.373 mL, 6.0 mmol) and heated at 55°-60° C. for 30 h. Thesolvents were evaporated under reduced pressure; the residue wastriturated in hexane and the solid was filtered, 1.85 g. The solid wasdissolved in hot water (8 mL) and the solution was diluted with acetoneuntil turbidity (70-80 mL). Two successive crystallizations gave 1.5 g,mp 220°-5° C. dec., 68% of the title compound; ir (KBr) ν_(max) : 1692cm⁻¹ (C=O); ¹ Hmr (D₂ O) δ: 2.40 (s, 3H, CH₃ COO), 3.37 (s, N--CH₃),3.39 (s, N--CH₃), 3.99 (s); uv (H₂ O) μ_(max) : 226 (ε13144). Anal.calcd for C₁₁ H₂₄ N₂ OSBrI: C 30.08, H 5.51, N 6.38; found: C 30.48, H5.53, N 6.86.

B. 1-(2-mercaptoethyl)-1,4,4-trimethylipiperazinium bischloride##STR132##

A mixture of 1-(2-acethylthioethyl)-1,4,4-trimethylpiperaziniumbromideiodide (1.84 g, 4.19 mmol) and 6N hydrochloric acid (15 mL) washeated at 57° C. under a nitrogen atmosphere for 2.5 h. The solution wasconcentrated under reduced pressure to dryness. The solid was suspendedin water (10 mL) and the well-stirred suspension was treated withpermutit S-1 Cl⁻ until a solution was obtained. The solution was pouredon a column (1.2×60 cm) of permutit S-1 Cl⁻. The column was eluted withwater (1.5 mL/min). The appropriate fractions were combined andlyophilized to give a white powder, 0.93 g, mp 190°-191° C., 85%; ir(nujol) νmax: 2460 (SH); 1Hmr (D₂ O) δ: 3.4 (s, N-CH₃), 3.45 (s,N--CH₃), 4.07 (s). Anal. calcd for C₉ H₂₂ N₂ SCl₂ ·0.75 H₂ O: C 39.34, H8.62, N 10.20, S 11.67; found C 39.48, H 8.39, N 10.55, S 11.15.

C. (5R,6S) paranitrobenzyl3-[2-(1,4,4-trimethyl1-piperazinium)-ethylthio]-6-(1R-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylatebischloride ##STR133##

To a cold (5° C.) solution of (5R,6S) paranitrobenzyl6-[1R-hydroxyethyl]-3,7-dioxo-1-azabicyclo(3.2.0) heptane-2-carboxylate(0.94 g, 2.7 mmol) in acetonitrile (3 mL) kept under a nitrogenatmosphere was added diisopropylethylamine (0.557 mL, 3.2 mmol) anddiphenyl chlorophosphate (0.663 mL, 3.2 mmol). The reaction mixture wasstirred at 5° C. for 30 min and treated with diisopropylethylamine(0.559 mL, 3.44 mmol) and an aqueous solution (4 mL) of1-(2-mercaptoethyl)-1,4,4-trimethylpiperazinium bischloride (0.90 g,3.44 mmol). After 1.25 h, diispropylethylamine (0.1 mL, 0.57 mmol) wasadded and the stirring was continued for 2 h. A part of the acetonitrilewas eliminated under reduced pressure and the resulting red mixture waschromatographed on PrepPak--500/C₁₈ (Water Associates) column with25-75% acetonitrile in water as eluting solvent to give a yellowishpowder (1.4 g) after lyophylization. The powder was solubilized in waterand the solution was passed on a column (1.2×58 cm) of permutit S-1 Cl⁻using water an eluting solvent. Lyophylization of the appropriatefractions gave 1.17 g of a powder that was repurified on a column ofPrepPak--500/C₁₈. Lyophylization of the appropriate fractions gave ayellowish powder, 0.80 (53%); ir (KBr)ν_(max) : 3400 (br, OH), 1770 (C=Oof the β-lactam), 1690 (C=O of PNB ester), 1605 (aromatic), 1515 (NO₂),1345 (NO₂) cm⁻¹ ; ¹ Hmr (D₂ O) δ: 1.26 (d, J=6.3 Hz, 3H, CH₃ CHOH), 3.39(s, NCH₃), 4.00 (s), 5.37 (br, s, CH₂ of PNB), 7.60 (d, J=8.6 Hz, 2H, Hoof PNB), 8.20 (d, J=8.7 Hz, 2H, Hm of PNB); uv (H₂ O)μ_(max) : 276(ε12094), 306 (ε10752). Anal. calcd. for C₂₅ H₃₆ N₄ O₆ SCl₂.3H₂ O:C46.51, H 6.56, N 8.68, S 4.97, Cl 10.98; found: C46.31, H 6.18, N 8.57,S 5.36, Cl 11.37.

D.(5R,6S)-3-[2-(1,4,4-trimethyl-1-piperazinium)ethylthio]-6-[1R-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylatechloride ##STR134##

A mixture of (5R,6S) paranitrobenzyl3-[2-(1,4,4-trimethyl-1-piperazinium)ethylthio]-6-[1R-hydroxyethyl]-7-oxo-1-azabicyclo(3.2.0)hept-2-ene-2-carboxylatebischloride (0.40 g, 0.68 mmol), phosphate buffer (30 mL, 0.05M, pH7.0), tetrahydrofuran (10 mL), ether (30 mL) and 10% palladium oncharcoal (0.40 g) was hydrogenated at 23° C. under 35 psi for 1 h. Thetwo phases were separated. The organic phase was extracted with water(10 mL). The aqueous phases were filtered on a Celite pad, washed withether (10 mL), concentrated under vacuum to 10 mL and chromatographed onPrePak-500/C₁₈ column (2.2×11 cm) with water as eluting solvent to give70 mg (25%) after lyophylization; ir (KBr)ν_(max) : 3400 (br, OH), 1755(C=O of the β-lactam), 1585 (carboxylate) cm⁻¹ ; ¹ Hmr (D₂ O)δ: 1.24(3H, d, J=6.3 Hz, CH₃ CHOH), 3.36 (s, NCH₃), 3.98 (s); uv (H₂ O) λ_(max):296(ε7987); [a]_(D) ²³ 35.9° (c, 0.30, H₂ O), T_(1/2) =9.8 h (measuredat a concentration of 10⁻⁴ M in phosphate buffer pH 7.4 at 36.8° C).

We claim:
 1. A compound of the formula ##STR135## wherein R⁸ is hydrogenand R¹ is hydrogen, ##STR136## or R¹ and R⁸ taken together represent##STR137## A is cyclopentylene, cyclohexylene or C₂ -C₆ alkyleneoptionally substituted by one or more C₁ -C₄ alkyl groups; and##STR138## wherein Y is hydrogen, C₁ -C₆ alkyl, hydroxy, --SC₁ -C₆alkyl, carboxyl, carbamoyl, chloro, bromo, iodo, fluoro or phenyl; or apharmaceutically acceptable salt thereof or a benzhydryl, allyl,p-nitrobenzyl, 2-naphthylmethyl, benzyl, trichloroethyl, silyl,phenacyl, p-methoxybenzyl, acetonyl, o-nitrobenzyl, 4-pyridylmethyl, C₁-C₆ alkyl, pivaloyloxymethyl, acetoxymethyl, phthalidyl, indanyl ormethoxymethyl ester.
 2. A compound according to claim 1 wherein R¹ is##STR139##
 3. A compound according to claim 1 wherein R¹ is ##STR140##and the absolute configuration is 5R, 6S, 8R.
 4. A compound according toclaim 1, 2 or 3 wherein A is ##STR141##
 5. A compound of the formula##STR142## wherein R⁸ is hydrogen and R¹ is hydrogen, ##STR143## or R¹and R⁸ taken together represent ##STR144## A is cyclopentylene,cyclohexylene or C₂ -C₆ alkylene optionally substituted by one or moreC₁ -C_(alkyl) groups; and ##STR145## wherein Y is hydrogen, C₁ -C₆alkyl, hydroxy, -SC₁ -C₆ alkyl, carboxyl, carbamoyl, chloro, bromo,iodo, fluoro or phenyl; or a pharmaceutically acceptable salt thereof ora benzhydryl, allyl, p-nitrobenzyl, 2-naphthylmethyl, benzyl,trichloroethyl, silyl, phenacyl, p-methoxybenzyl, acetonyl,o-nitrobenzyl, 4-pyridylmethyl, C₁ -C₆ alkyl, pivaloyloxymethyl,acetoxymethyl, phthalidyl, indanyl or methoxymethyl ester.
 6. A compoundaccording to claim 5 wherein R¹ is ##STR146##
 7. A compound according toclaim 5 wherein R¹ is ##STR147## and the absolute configuration is 5R,6S, 8R.
 8. A compound according to claim 5, 6, or 7 wherein A is --CH₂CH₂ --, --CH₂ CH₂ CH₂ --, ##STR148##
 9. A compound of the formula##STR149## wherein R⁸ is hydrogen and R¹ is hydrogen, ##STR150## or R¹and R⁸ taken together represent ##STR151## A is cyclopentylene,cyclohexylene or C₂ -C₆ alkylene optionally substituted by one or moreC₁ -C₄ alkyl groups; and ##STR152## pharmaceutically acceptable saltthereof or a benzhydryl allyl, p-nitrobenzyl, 2-naphthylmethyl, benzyl,trichloroethyl, silyl, phenacyl, p-methoxybenzyl, acetonyl,o-nitrobenzyl, 4-pyridylmethyl, C₁ -C₆ alkyl, pivaloyloxymethyl,acetoxymethyl, phthalidyl, indanyl or methoxymethyl ester.
 10. Acompound according to claim 9 wherein R¹ is ##STR153##
 11. A compoundaccording to claim 9 wherein R¹ is ##STR154## and the absoluteconfiguration is 5R, 6S, 8R.
 12. A compound according to claim 9, 10,and 11 wherein A is --CH₂ CH₂ --, --CH₂ CH₂ CH₂ --, ##STR155##
 13. Acompound of the formula ##STR156## or a pharmaceutically acceptable saltthereof or a benzhydryl, allyl, p-nitrobenzyl, 2-naphthylmethyl, benzyl,trichloroethyl, silyl, phenacyl, p-methoxybenzyl, acetonyl,o-nitrobenzyl, 4-pyridylmethyl, C₁ -C₆ alkyl, pivaloyloxymethyl,acetoxymethyl, phthalidyl, indanyl or methoxymethyl ester.